`learncs.online` lessons mix text, interactive walkthroughs, video content, and small practice and homework problems.

Each one brings you one step closer to mastering the basics of computer science and programming.

Welcome to learncs.online! We're excited to join you as you start your journey in computer science and programming. Today!

Let's begin our journey in computer science by presenting two of the basic building blocks of computer programs: variables and data types.

Our journey continues as we examine how we can manipulate the data stored by variables in our programs.

One of the things that makes computers so powerful is their ability to make decisions. We'll explore that capability in our programs in this lesson.

Next we'll examine how to make our conditional statements a bit more complex, allowing us to make more interesting decisions based on data in our programs.

Let's learn about our first data structure: arrays, which put data values in order.

This lesson covers our last core computer capability: the ability to repeat something multiple times, very quickly.

Now we'll pull together everything we've learned so far and use our new skills to start solving real problems. Or, put another way, we'll start designing algorithms.

Let's pause for more practice with loops and algorithms, including several chances to get practice solving real problems.

As we begin writing algorithms, let's stop and discuss how to organize our code into reusable units called functions.

Let's examine errors, debugging, and maintaining a healthy mindset as you learn to work with computers.

Next we'll continue discussing functions and introduce several common algorithm patterns.

Let's pause for a bit more practice with functions before we continue our journey together.

In this lesson we'll explore the connections between functions and algorithms.

This lesson is on algorithms and strings, and gives us a bit more practice with both.

How many problems can nothing cause? Quite a few! We'll learn more about the nothing that is a huge problem in this lesson.

Let's reinforce what we know about strings by working with a few more problems together!

Our next lesson expands our ability to work with sequential data into multiple dimensions!

This lesson may be the most important of the entire semester, since it shows you how to use other people's code!

Next we'll learn how to use lists, a linear data structure but one that is a bit more useful than the arrays that we've been working with so far.

Let's get a bit more practice with collections, those basic data structures that are so useful.

Let's explore a bit of programming internals, specifically your code is tranformed before it is executed in a process known as compilation.

Let's explore a bit of programming internals, specifically your code is tranformed before it is executed in a process known as compilation.

Let's continue our discussion of objects by examining object methods.

Next we'll investigate how to enable encapsulation through visibility modifiers and setters and getters.

Next we'll continue understanding Kotlin objects by exploring companion objects.

Next we'll continue understanding Java objects by exploring the static keyword and its implications.

This lesson puts our new abilities with objects to use modeling a real-world system.

Our next lesson explores the relationships between classes established through inheritance.

What does it mean for two objects to be equal? And how do we copy them? In this lesson we'll find out.

Next we'll complete another data modeling exercise that pulls together everything that we've learned.

Let's combine what we know about polymorphism and references to deepen our understanding even further.

Next we'll begin learning how to work with exceptions by understanding how to handle them when they occur.

Let's continue to learn about exceptions by finding out how and when to generate our own errors.

Next we'll examine how to implement interfaces on our own classes.

This lesson explores lambda expressions, a terse way of implementing interfaces using anonymous classes.

Our next lesson starts the third half of the class, our exploration of data structures, algorithms, and algorithm analysis.

Now for a different take on lists, we'll examine lists that store the position of items using reference linking.

This lesson continues discussing linked lists and implement a few list methods together.

Next we'll introduce trees, which are both a commonly-used data structure and a great way to get practice with recursion.

This lesson begins our examination of sorting algorithms, which represent both a conceptual and an implementation challenge.

We'll continue in this lesson by examining Merge Sort, an interesting and efficient sorting algorithm.

Next we'll continue on to examine Quicksort, a new sorting algorithm with some very interesting characteristics. Then we'll review the sorting algorithms that we've learned together.

Let's apply some of the same ideas we've developing sorting to a new problem, search.

This lesson explores hashing, a mysterious and yet incredibly useful idea that is even included directly in our programming language!

This lesson is short and fun. Let's combine what we know about hashing, arrays, and linked lists to implement our own map.

Next we introduce a language feature that allows us to write both general and type-safe code.

This lesson explores map-reduce-filter collection processing patterns, which are well-supported by Kotlin and useful for performing transformations on data.

This lesson explores streams, an advanced programming pattern useful for performing transformations on data.

In this lesson we'll introduce graphs, another commonly-used data structure and another great way to practice with recursion.