Kotlin
Java
431 Kotlin questions for you to solve
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Hello, world!
Hello, Fall 2021!
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Hello, University of Sydney!
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Hello, learncs.online!
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Hello, world!
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Print That Number
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Print Without a Newline
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Quote That
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Skip a Line
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Three Line Greeting
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Welcome to CS 124!
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Variables and Types
Practice with Primitive Types
initializing variables
declaring variables
Practice with Primitive Types 2
initializing variables
declaring variables
Practice with Primitive Types 4
initializing variables
declaring variables
Practice with Variable Declaration and Initialization 0
initializing variables
declaring variables
Operations on Variables
Area Calculation
arithmetic
initializing variables
declaring variables
Fall 2021 Grade Calculation
arithmetic
initializing variables
declaring variables
Greet by Name
arithmetic
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Inspiration v. Perspiration
arithmetic
initializing variables
declaring variables
Conditional Expressions and Statements
Advertising Conditional
if-else statements
if statements
comparisons
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Is CS Amazing
if-else statements
if statements
comparisons
initializing variables
declaring variables
System.out.println
Simple Conditional
if-else statements
if statements
comparisons
System.out.println
Largest of Three
if statements
comparisons
modifying variables
initializing variables
declaring variables
System.out.println
Print Larger, Sometimes
nested conditionals
if-else statements
if statements
comparisons
System.out.println
Compound Conditionals
A Generous Curve
if-else-if statements
if-else statements
if statements
comparisons
arithmetic
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Center of the Universe
logical operators
reference equality
if-else statements
if statements
comparisons
System.out.println
Print Adult Or Not
logical operators
nested conditionals
if-else statements
if statements
comparisons
System.out.println
Quiz Score Advice
if-else-if statements
if-else statements
if statements
comparisons
System.out.println
Game Tiebreaker Snippet
if-else-if statements
nested conditionals
if-else statements
if statements
comparisons
modifying variables
Two Magical Numbers
logical operators
if-else statements
if statements
comparisons
initializing variables
declaring variables
System.out.println
Time to Decade
if-else-if statements
logical operators
if statements
comparisons
System.out.println
Arrays
Array Basics
accessing arrays
using arrays
modifying variables
initializing variables
declaring variables
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Loops
Array Snippet Sum
for loops
accessing arrays
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Number Loop
for loops
comparisons
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Reverse Print Same Line
for loops
accessing arrays
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Say It Again
for loops
comparisons
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Victory Loop
for loops
comparisons
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Array Count Odd Snippet
for loops
accessing arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Array Sum Even Snippet
for loops
accessing arrays
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Easy Peasy Loop
for loops
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Odd Range Sum
for loops
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Functions
Add One Function
return
declaring methods
arithmetic
Is Even
return
declaring methods
reference equality
comparisons
arithmetic
Is Odd
return
declaring methods
reference equality
comparisons
arithmetic
Make Ends
return
declaring methods
accessing arrays
using arrays
arithmetic
Make Last
return
declaring methods
accessing arrays
using arrays
arithmetic
modifying variables
initializing variables
declaring variables
Make Middle
return
declaring methods
accessing arrays
using arrays
arithmetic
Make Pi
return
declaring methods
using arrays
Mid Three
return
declaring methods
accessing arrays
using arrays
arithmetic
Middle Way
return
declaring methods
accessing arrays
using arrays
Plus Two
return
declaring methods
accessing arrays
using arrays
Reverse Three
return
declaring methods
accessing arrays
using arrays
Rotate Left 3
return
declaring methods
accessing arrays
using arrays
Sum 3
return
declaring methods
accessing arrays
using arrays
arithmetic
Sum Is Odd
return
declaring methods
reference equality
comparisons
arithmetic
Swap Ends
return
declaring methods
accessing arrays
using arrays
arithmetic
modifying variables
initializing variables
declaring variables
Two Last Digit
return
declaring methods
reference equality
comparisons
arithmetic
Accounting Calculator
return
declaring methods
for loops
accessing arrays
using arrays
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Bigger Two
return
declaring methods
accessing arrays
using arrays
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
Common End
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
arithmetic
Less 20
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Max End 3
return
declaring methods
accessing arrays
using arrays
if statements
comparisons
modifying variables
initializing variables
declaring variables
More 20
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Near 10
return
declaring methods
logical operators
comparisons
arithmetic
Or 35
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Overloaded Add
return
declaring methods
arithmetic
Overloaded Area
return
declaring methods
arithmetic
Overloaded Multiply
return
declaring methods
arithmetic
Reverse Print
return
declaring methods
for loops
accessing arrays
using arrays
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Same First Last
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
arithmetic
Sleep In
return
declaring methods
logical operators
Special Eleven
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Sum Double
return
declaring methods
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
firstLast6
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
arithmetic
Answer Cell
return
declaring methods
logical operators
if-else statements
if statements
Array Count Equal (One Dimensional)
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Catchup Quiz Grading
return
declaring methods
for loops
accessing arrays
using arrays
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Cigar Party
return
declaring methods
logical operators
if-else statements
if statements
comparisons
Front Piece
return
declaring methods
accessing arrays
using arrays
if-else-if statements
reference equality
if-else statements
if statements
comparisons
In Order
return
declaring methods
logical operators
if-else statements
if statements
comparisons
Make 2
return
declaring methods
accessing arrays
using arrays
if-else-if statements
reference equality
if-else statements
if statements
comparisons
modifying variables
initializing variables
declaring variables
Make Chocolate
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Makes 10
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Max Triple
return
declaring methods
accessing arrays
using arrays
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Old 35
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Parrot Trouble
return
declaring methods
logical operators
comparisons
Sorta Sum
return
declaring methods
logical operators
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
Sum 2
return
declaring methods
accessing arrays
using arrays
if statements
comparisons
variables assignment
modifying variables
initializing variables
declaring variables
Three Last Digit
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Two As One
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
int Max
return
declaring methods
if-else statements
if statements
comparisons
modifying variables
declaring variables
Array Front 9
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Array Is Doubled
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Caught Speeding
return
declaring methods
if-else-if statements
if-else statements
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Game Tiebreaker Function
return
declaring methods
if-else-if statements
nested conditionals
if-else statements
if statements
comparisons
Has 23
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
Icy Hot
return
declaring methods
logical operators
comparisons
In 1 to 10
return
declaring methods
logical operators
if-else statements
if statements
comparisons
In 10..20
return
declaring methods
logical operators
comparisons
In Order Equals
return
declaring methods
logical operators
if-else statements
if statements
comparisons
Lucky Sum
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
Make Bricks
return
declaring methods
logical operators
comparisons
arithmetic
Monkey Trouble
return
declaring methods
logical operators
if statements
No 23
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
No Triples
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Share Digit
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
Squirrel Play
return
declaring methods
logical operators
if-else statements
if statements
comparisons
Without Doubles
return
declaring methods
logical operators
reference equality
nested conditionals
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Array 123
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array 667
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
nested conditionals
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array All Pairs
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Date Fashion
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
comparisons
Double 23
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
Fix 23
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
modifying variables
Front 11
return
declaring methods
accessing arrays
using arrays
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Max Mod 5
return
declaring methods
if-else-if statements
reference equality
nested conditionals
if-else statements
if statements
comparisons
arithmetic
Start 1
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Tea Party
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
comparisons
arithmetic
Teen Sum
return
declaring methods
logical operators
if-else statements
if statements
comparisons
arithmetic
Array Is All Larger
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Blackjack
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
comparisons
arithmetic
Blue Ticket
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
Green Ticket
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Has Teen
return
declaring methods
logical operators
comparisons
Lone Teen
return
declaring methods
logical operators
comparisons
initializing variables
declaring variables
Max 10..20
return
declaring methods
logical operators
if statements
comparisons
modifying variables
initializing variables
declaring variables
Pos Neg
return
declaring methods
logical operators
if-else statements
if statements
comparisons
Letter Grade Printout
return
declaring methods
for loops
accessing arrays
using arrays
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Lone Sum
return
declaring methods
logical operators
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
In 30..50
return
declaring methods
logical operators
if statements
comparisons
Red Ticket
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Unlucky 1
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
arithmetic
More About Functions
Number Of Sum Combinations
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Practice with Functions
Array Count 9
enhanced for loop
return
declaring methods
for loops
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Array Range Sum
enhanced for loop
return
declaring methods
for loops
using arrays
logical operators
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Strings
Back Around
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
initializing variables
declaring variables
Endsly
dotted method calls
dot notation
Strings
return
declaring methods
First Half
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Hello Name
Strings
return
declaring methods
arithmetic
Make ABBA
Strings
return
declaring methods
arithmetic
Make Out Word
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Make Tags
Strings
return
declaring methods
arithmetic
Middle Three
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Middle Two
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Missing Char
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
initializing variables
declaring variables
Mix Start
dotted method calls
dot notation
Strings
return
declaring methods
Non Start
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Reformat a Phone Number
dotted method calls
dot notation
Strings
return
declaring methods
accessing arrays
using arrays
arithmetic
initializing variables
declaring variables
Right 2
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Rotate Left 2
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Start Hi
dotted method calls
dot notation
Strings
return
declaring methods
String Name Occupation Parsing
dotted method calls
dot notation
Strings
return
declaring methods
accessing arrays
using arrays
arithmetic
initializing variables
declaring variables
Without End
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
nTwice
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
Combo String
dotted method calls
dot notation
Strings
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
Diff 21
dotted method calls
dot notation
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
Double Array Range and Sum String
Strings
enhanced for loop
calling methods
return
declaring methods
for loops
accessing arrays
using arrays
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Double Char
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Email to NetID
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
accessing arrays
using arrays
initializing variables
declaring variables
equality
Ends Up
dotted method calls
dot notation
Strings
return
declaring methods
if statements
comparisons
arithmetic
initializing variables
declaring variables
Every Nth
dotted method calls
dot notation
Strings
return
declaring methods
for loops
comparisons
variables assignment
modifying variables
initializing variables
declaring variables
Extra Front
dotted method calls
dot notation
Strings
return
declaring methods
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
First Two
dotted method calls
dot notation
Strings
return
declaring methods
if statements
comparisons
Front 22
dotted method calls
dot notation
Strings
return
declaring methods
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Front 3
dotted method calls
dot notation
Strings
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
modifying variables
declaring variables
Front Again
dotted method calls
dot notation
Strings
return
declaring methods
if statements
comparisons
arithmetic
equality
Last Two
dotted method calls
dot notation
Strings
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
Last Value From String
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
modifying variables
initializing variables
declaring variables
Near Hundred
dotted method calls
dot notation
return
declaring methods
logical operators
comparisons
arithmetic
Repeat End
dotted method calls
dot notation
Strings
return
declaring methods
for loops
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Repeat Front
dotted method calls
dot notation
Strings
return
declaring methods
for loops
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
String Bits
dotted method calls
dot notation
Strings
return
declaring methods
for loops
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
String Flip Halves
dotted method calls
dot notation
Strings
return
declaring methods
reference equality
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
String Reverse
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
String Splotion
dotted method calls
dot notation
Strings
return
declaring methods
for loops
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
String Times
Strings
return
declaring methods
for loops
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
Sum Limit
dotted method calls
dot notation
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
The End
dotted method calls
dot notation
Strings
return
declaring methods
if-else statements
if statements
arithmetic
Without End 2
dotted method calls
dot notation
Strings
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
delDel
dotted method calls
dot notation
Strings
return
declaring methods
if statements
arithmetic
notString
dotted method calls
dot notation
Strings
return
declaring methods
if statements
arithmetic
oneTwo
dotted method calls
dot notation
Strings
return
declaring methods
for loops
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
At First
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
Close 10
dotted method calls
dot notation
return
declaring methods
if-else-if statements
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
Count Hi
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Count XX
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Double X
dotted method calls
dot notation
Strings
return
declaring methods
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
End Other
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
equality
Front Times
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Has Bad
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
comparisons
Last Chars
dotted method calls
dot notation
Strings
return
declaring methods
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Less By 10
dotted method calls
dot notation
return
declaring methods
logical operators
comparisons
arithmetic
Min Cat
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
Mini Rotation
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Prefix Again
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Reformat Name and Age Records
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if-else statements
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
See Color
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if-else statements
if statements
Start Word
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
if-else statements
if statements
comparisons
String Match
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Two Char
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
if-else statements
if statements
comparisons
arithmetic
Without 2
dotted method calls
dot notation
Strings
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
equality
Without X
dotted method calls
dot notation
Strings
return
declaring methods
if statements
arithmetic
modifying variables
initializing variables
declaring variables
altPairs
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Bob There
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Cat Dog
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if-else-if statements
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Has 271
dotted method calls
dot notation
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Last2
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Love 8
dotted method calls
dot notation
return
declaring methods
logical operators
reference equality
comparisons
arithmetic
Mario Bricks
Strings
nested loops
nested loops
return
declaring methods
for loops
if-else statements
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Same Star Character
dotted method calls
dot notation
Strings
return
declaring methods
continue
for loops
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
conCat
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
arithmetic
plus Out
dotted method calls
dot notation
Strings
return
declaring methods
for loops
logical operators
if-else statements
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
stringE
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
xy Balance
dotted method calls
dot notation
Strings
return
declaring methods
continue
for loops
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
xyz Middle
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
equality
Count Code
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Fizz String
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
Fizz String 2
Strings
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
Mix String
dotted method calls
dot notation
Strings
return
declaring methods
for loops
if-else-if statements
logical operators
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Small Word Filter With Array
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Southern Hemisphere Seasons
Strings
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Start Oz
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
String X
dotted method calls
dot notation
Strings
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
String Yak
dotted method calls
dot notation
Strings
return
declaring methods
for loops
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Sydney Semester Converter
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if-else statements
if statements
equality
xyz There
dotted method calls
dot notation
Strings
return
declaring methods
for loops
logical operators
reference equality
nested conditionals
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Alarm Clock
Strings
return
declaring methods
logical operators
reference equality
nested conditionals
if-else statements
if statements
comparisons
Close Far
dotted method calls
dot notation
return
declaring methods
logical operators
comparisons
arithmetic
Drop Bear Safety
Strings
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
String Is Alphabetic
dotted method calls
dot notation
Strings
return
declaring methods
continue
for loops
logical operators
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Without X2
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
reference equality
if statements
comparisons
variables assignment
modifying variables
initializing variables
declaring variables
deFront
dotted method calls
dot notation
Strings
return
declaring methods
logical operators
reference equality
if statements
comparisons
variables assignment
modifying variables
initializing variables
declaring variables
Star Out
dotted method calls
dot notation
Strings
return
declaring methods
continue
for loops
if-else-if statements
logical operators
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Evenly Spaced
dotted method calls
dot notation
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
Rock Paper Scissors
Strings
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Aussie Slang Translator
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if-else statements
if statements
equality
Deadly Animal Ranking
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
equality
Algorithms and Strings
Print Number Summary
primitive type casting
dotted method calls
dot notation
Strings
enhanced for loop
declaring methods
continue
for loops
reference equality
if-else statements
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Decimal to Binary String
primitive type casting
dotted method calls
dot notation
Strings
return
declaring methods
break
while loops
reference equality
if-else statements
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
null
Reformat a Name
working with null
dotted method calls
dot notation
Strings
return
declaring methods
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
String Last Name
working with null
dotted method calls
dot notation
Strings
return
declaring methods
accessing arrays
using arrays
reference equality
if statements
comparisons
initializing variables
declaring variables
Array Sum (One Dimensional)
working with null
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
String Character Sum
working with null
dotted method calls
dot notation
Strings
return
declaring methods
for loops
reference equality
if statements
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
String Doubled
working with null
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Array Count Greater Than 1D
working with null
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Array Is Sorted
working with null
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array Sum (Two Dimensional)
working with null
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
Array Sum Even (One Dimensional)
working with null
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Calculate Grocery Bill
working with null
dotted method calls
dot notation
Strings
enhanced for loop
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Rot 13 Encryption
working with null
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
String Equality
working with null
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
equality
Array Count Equal (Two Dimensional)
working with null
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Array Count Greater Than (Two Dimensional)
working with null
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Array Count Inversions
working with null
nested loops
nested loops
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array Count Not Equal (Two Dimensional)
working with null
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Array Max (1D)
working with null
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Football CSV
working with null
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Game CSV Max First
working with null
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
modifying variables
initializing variables
declaring variables
LongToShort
working with null
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
String Rotate Right
working with null
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Count Decreasing Sequences
working with null
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
nested conditionals
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
String Rotate Left
working with null
dotted method calls
dot notation
Strings
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Sum Array Odds
working with null
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array All Factors
working with null
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Array Is Peak
working with null
return
declaring methods
for loops
accessing arrays
using arrays
if-else-if statements
logical operators
reference equality
nested conditionals
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array Is Valley
working with null
return
declaring methods
for loops
accessing arrays
using arrays
if-else-if statements
logical operators
reference equality
nested conditionals
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Count DNA Subsequence
working with null
dotted method calls
dot notation
Strings
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
equality
Array Same Size (Two Dimensional)
working with null
return
declaring methods
for loops
accessing arrays
if-else-if statements
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Binary String Is Balanced
working with null
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
for loops
logical operators
reference equality
nested conditionals
if-else statements
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Game CSV Sum
working with null
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
if-else-if statements
reference equality
if-else statements
if statements
comparisons
variables assignment
modifying variables
initializing variables
declaring variables
equality
Check Top Ten Movies
working with null
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Swap Section
working with null
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Multidimensional Arrays
Array Fill 3 Pattern
using multi-dimensional arrays
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Array Transpose
using multi-dimensional arrays
working with null
nested loops
nested loops
assert statements
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Symmetric Matrix
using multi-dimensional arrays
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
2D Array Max Subarray Sum
using multi-dimensional arrays
working with null
nested loops
nested loops
assert statements
return
declaring methods
for loops
accessing arrays
logical operators
reference equality
if statements
comparisons
variables assignment
variable operations
modifying variables
initializing variables
declaring variables
Find Double; Ignore Diagonals
using multi-dimensional arrays
working with null
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
reference equality
nested conditionals
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Tic-Tac-Toe
using multi-dimensional arrays
return
declaring methods
for loops
accessing arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Lists and Type Parameters
Last In List
type parameters
dotted method calls
dot notation
return
declaring methods
arithmetic
Count Valid Strings
type parameters
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
if statements
variable operations
modifying variables
initializing variables
declaring variables
Small Word Filter With List
type parameters
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
return
declaring methods
for loops
using arrays
if statements
comparisons
initializing variables
declaring variables
Maps and Sets
Identify a Suspect
type parameters
dotted method calls
dot notation
creating objects
Strings
return
declaring methods
initializing variables
declaring variables
Word Count With Map
type parameters
boxing classes
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
return
declaring methods
for loops
using arrays
arithmetic
initializing variables
declaring variables
Cache Handler
type parameters
boxing classes
using multi-dimensional arrays
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
return
declaring methods
for loops
accessing arrays
using arrays
if statements
comparisons
initializing variables
declaring variables
List to Set
type parameters
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
assert statements
return
declaring methods
for loops
reference equality
comparisons
initializing variables
declaring variables
Map Has Duplicate Values
type parameters
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
return
declaring methods
for loops
if statements
initializing variables
declaring variables
Word Lengths With Map
type parameters
boxing classes
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
assert statements
return
declaring methods
for loops
using arrays
reference equality
comparisons
initializing variables
declaring variables
Calculate GPA
type parameters
boxing classes
dotted method calls
dot notation
Strings
enhanced for loop
return
declaring methods
for loops
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Script Parser
type parameters
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
initializing variables
declaring variables
Section Lists to Map
type parameters
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
nested loops
nested loops
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
comparisons
variable operations
modifying variables
initializing variables
declaring variables
String Duplicate Words Ignore Case
type parameters
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
assert statements
return
declaring methods
for loops
using arrays
reference equality
if statements
comparisons
initializing variables
declaring variables
Encapsulation
Counter Object
public and private
class field
declaring classes
return
declaring methods
variable operations
modifying variables
Format Date Method
public and private
declaring classes
import statements
dotted method calls
dot notation
Strings
return
declaring methods
Multiplier Single Method
public and private
declaring classes
return
declaring methods
arithmetic
Course Hash Code
final fields
public and private
constructors
class field
declaring classes
import statements
dotted method calls
dot notation
Strings
return
declaring methods
modifying variables
Flip Flop Object
public and private
constructors
class field
declaring classes
return
declaring methods
logical operators
modifying variables
Flop Flip Object
public and private
constructors
class field
declaring classes
return
declaring methods
logical operators
modifying variables
Last 8
final fields
public and private
class field
declaring classes
return
declaring methods
accessing arrays
using arrays
arithmetic
modifying variables
Object with Public Value
writing getters
working with null
dotted variable accesses
dot notation
assert statements
return
declaring methods
reference equality
comparisons
Simple Object Method
public and private
writing setters
class field
declaring classes
return
declaring methods
arithmetic
modifying variables
Simple Object Method 2
public and private
writing setters
class field
declaring classes
return
declaring methods
arithmetic
modifying variables
Subtracter Single Method
public and private
writing setters
class field
declaring classes
return
declaring methods
variables assignment
modifying variables
Toggler Object
public and private
constructors
class field
declaring classes
return
declaring methods
logical operators
modifying variables
Compare Date Strings
public and private
declaring classes
import statements
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if-else statements
if statements
comparisons
initializing variables
declaring variables
Kotlin Simple Object Field
public and private
writing setters
writing getters
constructors
class field
declaring classes
return
declaring methods
modifying variables
Last Odd 8
final fields
public and private
class field
declaring classes
return
declaring methods
accessing arrays
reference equality
if statements
comparisons
arithmetic
modifying variables
Points Class
public and private
constructors
class field
declaring classes
return
declaring methods
variables assignment
modifying variables
Round Sum
public and private
calling methods
return
declaring methods
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
Simple Object Method (Kotlin)
public and private
writing setters
constructors
class field
declaring classes
return
declaring methods
arithmetic
modifying variables
Simple Object Method 2 (Kotlin)
public and private
writing setters
constructors
class field
declaring classes
return
declaring methods
arithmetic
modifying variables
Guessing Game
writing getters
working with null
dotted method calls
dot notation
assert statements
return
declaring methods
for loops
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Last 4 In Order
final fields
public and private
class field
declaring classes
return
declaring methods
for loops
accessing arrays
using arrays
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Max Double
public and private
constructors
class field
declaring classes
return
declaring methods
if statements
comparisons
modifying variables
Min Int
public and private
constructors
class field
declaring classes
return
declaring methods
if statements
comparisons
modifying variables
Mystery Class 1
final fields
public and private
constructors
class field
declaring classes
return
declaring methods
reference equality
comparisons
variable operations
modifying variables
Temperature Getters and Setters
final fields
public and private
writing setters
writing getters
constructors
class field
declaring classes
Strings
return
declaring methods
modifying variables
Even Counter
public and private
writing getters
constructors
class field
declaring classes
assert statements
return
declaring methods
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
Kotlin Simple Object Field 2
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
Strings
assert statements
return
declaring methods
reference equality
comparisons
modifying variables
Score Tracker
public and private
class field
declaring classes
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
comparisons
variables assignment
modifying variables
No Teen Sum
public and private
calling methods
return
declaring methods
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
Course Getters and Setters
final fields
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
Strings
assert statements
return
declaring methods
reference equality
comparisons
modifying variables
Dog Getters and Setters
final fields
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
Strings
assert statements
return
declaring methods
reference equality
comparisons
modifying variables
Restaurant Getters and Setters
final fields
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
Strings
assert statements
return
declaring methods
reference equality
comparisons
modifying variables
SimpleArrayList get and set
final fields
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
assert statements
return
declaring methods
accessing arrays
using arrays
logical operators
reference equality
comparisons
modifying variables
SimpleArrayList add
public and private
writing getters
constructors
class field
declaring classes
working with null
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Companion Objects
Format Date
static methods
public and private
declaring classes
import statements
dotted method calls
dot notation
Strings
return
declaring methods
Static Adder
static methods
public and private
declaring classes
return
declaring methods
arithmetic
Array Deep Copy
static methods
public and private
declaring classes
working with null
creating objects
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Invert a Map
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
assert statements
return
declaring methods
for loops
reference equality
comparisons
initializing variables
declaring variables
Mystery Method 2
static methods
public and private
declaring classes
dotted method calls
dot notation
enhanced for loop
return
declaring methods
for loops
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Object Array Shallow Copy
static methods
public and private
declaring classes
working with null
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Person Encourager
static methods
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dot notation
Strings
assert statements
return
declaring methods
reference equality
comparisons
arithmetic
modifying variables
All or Nothing
static methods
public and private
declaring classes
creating objects
return
declaring methods
for loops
accessing arrays
using arrays
if-else statements
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Count Letters with Map
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
assert statements
return
declaring methods
continue
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Mystery Method 1
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
reference equality
if-else statements
if statements
comparisons
arithmetic
Object v. Reference Equality
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
equality
Same Count
static methods
public and private
declaring classes
working with null
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Dog Is Older
static methods
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dot notation
assert statements
return
declaring methods
reference equality
comparisons
modifying variables
OurComparable Max
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Quicksort Partition (First Value)
static methods
public and private
declaring classes
working with null
return
declaring methods
for loops
accessing arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Same or Different
static methods
public and private
declaring classes
working with null
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
Test Array Sum
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
assert statements
declaring methods
using arrays
reference equality
comparisons
FizzBuzz
static methods
public and private
declaring classes
declaring methods
for loops
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
FozzBuzz
static methods
public and private
declaring classes
declaring methods
for loops
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
List Unique Items
static methods
public and private
declaring classes
type parameters
import statements
dotted method calls
dot notation
nested loops
nested loops
return
declaring methods
continue
break
for loops
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
Return an Exception
static methods
public and private
declaring classes
creating objects
assert statements
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Test Rotate String
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
assert statements
declaring methods
reference equality
comparisons
equality
Inheritance
Simple Cat Inheritance
calling super
extending classes
final fields
public and private
constructors
class field
declaring classes
working with null
Strings
assert statements
calling methods
return
declaring methods
reference equality
comparisons
arithmetic
modifying variables
Simple Dog Inheritance
calling super
extending classes
final fields
public and private
constructors
class field
declaring classes
Strings
assert statements
calling methods
return
declaring methods
comparisons
arithmetic
modifying variables
Simple Person Inheritance
calling super
extending classes
final fields
public and private
writing getters
constructors
class field
declaring classes
Strings
assert statements
calling methods
return
declaring methods
comparisons
modifying variables
SimpleLinkedList count
extending classes
public and private
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
return
declaring methods
for loops
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
SimpleLinkedList find
extending classes
public and private
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
return
declaring methods
for loops
reference equality
if statements
comparisons
initializing variables
declaring variables
equality
Math Course Inheritance
calling super
extending classes
public and private
writing getters
constructors
class field
declaring classes
working with null
Strings
assert statements
calling methods
return
declaring methods
reference equality
comparisons
arithmetic
modifying variables
Polymorphism
Circle Shape
instanceof type checking
calling super
extending classes
final fields
public and private
constructors
class field
declaring classes
dotted variable accesses
dot notation
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
Person Whisperer
instanceof type checking
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if-else statements
if statements
Pet Whisperer
instanceof type checking
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if-else statements
if statements
Polymorphic Greeter
instanceof type checking
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if statements
arithmetic
Polymorphic Orderer
instanceof type checking
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
Strings
return
declaring methods
if-else-if statements
if statements
arithmetic
Square Shape
instanceof type checking
object type casting
calling super
extending classes
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dot notation
calling methods
return
declaring methods
if-else-if statements
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Car Equality
instanceof type checking
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
logical operators
reference equality
if statements
comparisons
modifying variables
equality
Restaurant Equality
instanceof type checking
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
logical operators
reference equality
if statements
comparisons
modifying variables
equality
SimpleArrayList equals
instanceof type checking
object type casting
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
Song Equality
instanceof type checking
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
logical operators
reference equality
if statements
comparisons
modifying variables
equality
Course Equality
instanceof type checking
this keyword
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
logical operators
reference equality
if statements
comparisons
modifying variables
equality
Catching Exceptions
Exception Recorder
try-catch
static methods
public and private
declaring classes
dotted method calls
dot notation
return
declaring methods
while loops
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
System.out.println
Multi Catcher
try-catch
static methods
public and private
declaring classes
dotted method calls
dot notation
return
declaring methods
while loops
Catching Exceptions
try-catch
static methods
public and private
declaring classes
dotted method calls
dot notation
return
declaring methods
Test Array Max
try-catch
instanceof type checking
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
assert statements
declaring methods
using arrays
reference equality
comparisons
Throwing Exceptions
Array Pairwise Sum
throwing exceptions
working with null
creating objects
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Escape a Maze
throwing exceptions
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
creating objects
nested loops
nested loops
return
declaring methods
while loops
logical operators
reference equality
if statements
comparisons
SimpleLinkedList Count Equal
throwing exceptions
extending classes
public and private
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
creating objects
return
declaring methods
for loops
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
SimpleLinkedList Count Not Equal
throwing exceptions
extending classes
public and private
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
creating objects
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
Count Repeated Words With Map Case-Insensitive
throwing exceptions
type parameters
boxing classes
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
return
declaring methods
for loops
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Map Sum Longer Than
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
variables assignment
modifying variables
initializing variables
declaring variables
OurComparable Is Sorted
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Pentagon Shape
throwing exceptions
instanceof type checking
calling super
extending classes
final fields
public and private
constructors
class field
declaring classes
dotted variable accesses
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
Restaurant Hash Code
throwing exceptions
final fields
public and private
constructors
class field
declaring classes
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
return
declaring methods
logical operators
reference equality
if statements
comparisons
modifying variables
BinarySearcher Array (int)
throwing exceptions
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
creating objects
return
declaring methods
while loops
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Insertion Sort (int)
throwing exceptions
static methods
public and private
declaring classes
working with null
creating objects
nested loops
nested loops
return
declaring methods
break
for loops
accessing arrays
reference equality
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Selection Sort
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Guessing Game With Tries
throwing exceptions
final fields
public and private
writing getters
constructors
class field
declaring classes
creating objects
return
declaring methods
logical operators
reference equality
if-else statements
if statements
comparisons
variable operations
modifying variables
Isomorphic Strings With Map
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
return
declaring methods
for loops
if-else-if statements
logical operators
reference equality
nested conditionals
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
Cities Are Connected
throwing exceptions
final fields
public and private
constructors
class field
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
enhanced for loop
nested loops
nested loops
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
variable operations
modifying variables
initializing variables
declaring variables
PingPonger Class
throwing exceptions
public and private
constructors
class field
declaring classes
dotted method calls
dot notation
creating objects
Strings
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
modifying variables
equality
Isomorphic Strings Without Map
throwing exceptions
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
creating objects
Strings
nested loops
nested loops
return
declaring methods
continue
for loops
accessing arrays
using arrays
logical operators
reference equality
nested conditionals
if-else statements
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Library Class
throwing exceptions
final fields
public and private
class field
declaring classes
type parameters
boxing classes
import statements
dotted method calls
dot notation
creating objects
return
declaring methods
logical operators
reference equality
nested conditionals
if statements
comparisons
initializing variables
declaring variables
Restaurant Capacity Manager
checked exceptions
throwing exceptions
final fields
public and private
constructors
class field
declaring classes
creating objects
return
declaring methods
if statements
comparisons
variables assignment
arithmetic
modifying variables
Using Interfaces
Course CSV to Courses
final classes
static methods
final fields
public and private
writing getters
constructors
class field
declaring classes
working with null
dotted method calls
dot notation
creating objects
Strings
assert statements
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
comparisons
variable operations
modifying variables
initializing variables
declaring variables
equality
Implementing Interfaces
Last Odd Interface
implementing interfaces
public and private
class field
declaring classes
return
declaring methods
reference equality
comparisons
arithmetic
modifying variables
Running Total Interface
implementing interfaces
public and private
class field
declaring classes
return
declaring methods
variables assignment
modifying variables
OurComparable Car
implementing interfaces
throwing exceptions
instanceof type checking
object type casting
final fields
public and private
constructors
class field
declaring classes
dotted variable accesses
dotted method calls
dot notation
creating objects
assert statements
return
declaring methods
logical operators
if statements
comparisons
modifying variables
initializing variables
declaring variables
String Length Comparable Parameterized
implementing interfaces
using the Comparable interface
final fields
public and private
constructors
class field
declaring classes
type parameters
working with null
dotted variable accesses
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
modifying variables
Both Greater Comparable
implementing interfaces
using the Comparable interface
final fields
public and private
constructors
class field
declaring classes
type parameters
dotted variable accesses
dot notation
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
comparisons
modifying variables
String Length Comparable
implementing interfaces
using the Comparable interface
instanceof type checking
object type casting
final fields
public and private
constructors
class field
declaring classes
working with null
dotted variable accesses
dotted method calls
dot notation
Strings
assert statements
return
declaring methods
if-else-if statements
reference equality
if-else statements
if statements
comparisons
modifying variables
initializing variables
declaring variables
OurComparable Dog
implementing interfaces
throwing exceptions
instanceof type checking
final fields
public and private
constructors
class field
declaring classes
dotted variable accesses
dot notation
creating objects
assert statements
return
declaring methods
if-else-if statements
logical operators
if-else statements
if statements
comparisons
modifying variables
Anonymous Classes
Bracket an Anonymous Class
anonymous classes
static methods
public and private
declaring classes
creating objects
return
declaring methods
String Both Ways Anonymous Class
anonymous classes
throwing exceptions
static methods
public and private
declaring classes
working with null
dotted method calls
dot notation
creating objects
Strings
return
declaring methods
for loops
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Lambda Expressions
Adder with Lambda
lambda expressions
static methods
public and private
declaring classes
return
declaring methods
arithmetic
Subtracter with Lambda
lambda expressions
static methods
public and private
declaring classes
return
declaring methods
arithmetic
Linked Lists
SimpleLinkedList set
inner classes
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
dotted variable accesses
dot notation
creating objects
assert statements
calling methods
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
SimpleLinkedList add
inner classes
public and private
writing setters
writing getters
constructors
class field
declaring classes
working with null
dotted variable accesses
dot notation
creating objects
assert statements
calling methods
return
declaring methods
for loops
accessing arrays
using arrays
logical operators
reference equality
if-else statements
if statements
comparisons
variables assignment
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Recursion
Array Select Nth Smallest
static methods
public and private
declaring classes
boxing classes
import statements
dotted method calls
dot notation
calling methods
return
declaring methods
accessing arrays
using arrays
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
Mergesort
throwing exceptions
extending classes
public and private
declaring classes
working with null
creating objects
calling methods
return
declaring methods
using arrays
reference equality
if statements
comparisons
arithmetic
Recursive Factorial
throwing exceptions
static methods
public and private
declaring classes
creating objects
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
Recursive Range Sum
throwing exceptions
static methods
public and private
declaring classes
creating objects
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
Trees and Recursion
Binary Tree Size
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
reference equality
if statements
comparisons
arithmetic
BinaryTree Count Greater Than
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
BinaryTree Count Not Equal
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
BinaryTree Even Sum
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
reference equality
if-else statements
if statements
comparisons
arithmetic
BinaryTree Negative Sum
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
return
declaring methods
reference equality
if-else statements
if statements
comparisons
arithmetic
BinaryTree Odd Sum
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
reference equality
if-else statements
if statements
comparisons
arithmetic
Binary Tree Count Leaves
static methods
public and private
declaring classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Binary Tree Count Non-Leaves
static methods
public and private
declaring classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Binary Tree Combine Strings
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
calling methods
return
declaring methods
reference equality
if statements
comparisons
arithmetic
Binary Tree Count Children Sum to Negative
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
BinaryTree Count Equal Children
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
equality
BinaryTree to List
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
reference equality
if statements
comparisons
initializing variables
declaring variables
BinaryTree to Map
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
Binary Tree Combine Even Strings
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
Strings
calling methods
return
declaring methods
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
Binary Tree Count Equal to Child
static methods
public and private
declaring classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
modifying variables
initializing variables
declaring variables
equality
Binary Tree Sum Right Child
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
Binary Tree Count Children Sum to Even
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
variables assignment
arithmetic
modifying variables
initializing variables
declaring variables
BinaryTree Values at Level (int)
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
return
declaring methods
logical operators
reference equality
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
BinaryTree Balanced
throwing exceptions
static methods
public and private
declaring classes
import statements
working with null
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
logical operators
reference equality
if statements
comparisons
arithmetic
initializing variables
declaring variables
Binary Tree Any Same Shape
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
if-else-if statements
logical operators
reference equality
if-else statements
if statements
comparisons
Binary Tree Count Increasing
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
calling methods
return
declaring methods
logical operators
reference equality
nested conditionals
if statements
comparisons
arithmetic
Binary Tree Search Path
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
calling methods
return
declaring methods
logical operators
reference equality
if-else statements
if statements
comparisons
initializing variables
declaring variables
equality
map-reduce-filter
Double Up
lambda expressions
type parameters
dotted method calls
dot notation
Strings
return
declaring methods
arithmetic
initializing variables
declaring variables
Double Up Null
lambda expressions
type parameters
working with null
dotted method calls
dot notation
Strings
return
declaring methods
reference equality
if-else statements
if statements
comparisons
arithmetic
initializing variables
declaring variables
Graphs
Undirected Graph Size
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
enhanced for loop
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
initializing variables
declaring variables
Unweighted Graph Is Undirected
throwing exceptions
static methods
public and private
declaring classes
type parameters
import statements
working with null
dotted method calls
dot notation
creating objects
enhanced for loop
nested loops
nested loops
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
declaring variables
Undirected Graph Neighborhood Count
throwing exceptions
static methods
public and private
declaring classes
type parameters
boxing classes
import statements
working with null
dotted method calls
dot notation
creating objects
enhanced for loop
return
declaring methods
for loops
logical operators
reference equality
if statements
comparisons
arithmetic
variable operations
modifying variables
initializing variables
declaring variables
Java
Kotlin
JavaJavaJava