Kotlin

Java

Your Instructors

Geoffrey Challen is the primary creator and maintainer of learncs.online.

Geoffrey authored the lesson content and homework problems, and created and maintains the backend systems that power the playgrounds, explanations, problems, and other interactive website content. You can find more details about the course infrastructure and more complete credits here.

However, in the years since the original materials were created, other students and faculty from the University of Illinois, students from other institutions, and learncs.online students have contributed to the learncs.online materials. All contributors are listed below, starting with verified instructors.

If you'd like to contribute, please get in touch!

Instructors

Geoffrey Challen

he, him, his

Personal Website

Full Profile

Kotlin

Java

872 contributions

Colleen Lewis

Kotlin

Java

326 contributions

Chris Taylor

Java

34 contributions

Ellen Spertus

she, her, hers

Teaching Professor, Khoury College of Computer Sciences, Northeastern University

Personal Website

Full Profile

Kotlin

Java

25 contributions

Teacher

Rohith Sanjay

Kotlin

Java

115 contributions

Carlos Inigo Fernandez

Java

41 contributions

Thomas Cai

Kotlin

Java

36 contributions

Miguel Fernandez

Kotlin

Java

30 contributions

Jackie Chan

Kotlin

Java

28 contributions

Tutor

Rachanon Petchoo

Java

22 contributions

Conor Cunningham

Java

22 contributions

Arnav Sethi

Java

21 contributions

Haosen Yao

Kotlin

Java

21 contributions

Carl Edwards

Java

21 contributions

Benjamin Chang

Kotlin

19 contributions

Jacob Chang

Kotlin

Java

19 contributions

Aden Krakman

Java

17 contributions

Ying Chen

Java

17 contributions

Ruisong Li

Kotlin

Java

16 contributions

Rohan Gudipaty

Java

16 contributions

Hyunho Kim

Kotlin

Java

16 contributions

Patrick Cunningham

Java

16 contributions

Assistant

Sam Erens

Kotlin

Java

15 contributions

Nancy Jia

Kotlin

Java

13 contributions

Tom Sui

Java

13 contributions

Alistair Forsyth

Kotlin

13 contributions

Ritvik Sood

Java

13 contributions

Justin Bai

Kotlin

13 contributions

Yuxuan Chen

Java

12 contributions

Carolyn Zeng

Kotlin

Java

12 contributions

Kaan Yigit

Java

12 contributions

Michael Rheintgen

Kotlin

12 contributions

Boyang Sun

Java

11 contributions

Matt Twyman

Java

11 contributions

Maxwell Yang

Java

11 contributions

Elijah Mock

Kotlin

Java

11 contributions

Jay Chen

Java

11 contributions

Hrishikesh Kalyanaraman

Java

10 contributions

Collin Fox

Java

10 contributions

Zijing Wei

Kotlin

Java

10 contributions

Zuhair Ali

Kotlin

Java

10 contributions

Kevin Liu

Java

10 contributions

Zainab Memon

Java

10 contributions

Saashin Subramaniam

Java

10 contributions

Sriya Mikkilineni

Java

9 contributions

Ben Clarage

Kotlin

Java

9 contributions

Niharika Bhattacharjee

Java

9 contributions

Prith Balaji

Java

9 contributions

Jake Cumberland

Java

9 contributions

Christopher Sahyouni

Java

9 contributions

Cristian Flores

Java

8 contributions

Arghya Srivastav

Java

8 contributions

Anushree Tibrewal

Java

8 contributions

Nathaniel Zukowski

Java

8 contributions

Anagha Shenoy

Kotlin

8 contributions

Daniel Gutierrez

Java

8 contributions

Rohan Shah

Kotlin

8 contributions

Maaheen Maajed

Kotlin

Java

7 contributions

Lexi Ippolito

Java

7 contributions

Adelia Solarman

Java

7 contributions

Alex Gong

Java

7 contributions

Meera Jagannathan

Java

7 contributions

Justin Kim

Kotlin

Java

7 contributions

Brendan Biernacki

Java

7 contributions

Daniel Song

Kotlin

Java

7 contributions

Chris Whamond

Kotlin

Java

7 contributions

Kaiwen Mo

Java

7 contributions

Anirudh Kumar

Java

6 contributions

Grace Jia

Kotlin

Java

6 contributions

Diego Taveras

Kotlin

6 contributions

Ishika Awachat

Java

6 contributions

Zhuoang Tao

Kotlin

Java

6 contributions

Ahmed Hasan

Kotlin

Java

6 contributions

Prem Dhoot

Java

6 contributions

Eugene Jang

Java

6 contributions

Anakin Dey

Java

6 contributions

Saagar Kolachina

Kotlin

Java

6 contributions

Amirthavarshini Sureshbabu

Java

6 contributions

Henry Tang

Java

6 contributions

Arpit Bansal

Kotlin

Java

6 contributions

Sunwoo Baek

Java

6 contributions

Helper

Jonathan You

Java

5 contributions

Delu Zhao

Java

5 contributions

Monica Para

Kotlin

Java

5 contributions

Amaan Mirza

Java

5 contributions

Mike Cheng

Kotlin

5 contributions

Harsh Deep

Java

5 contributions

Arjun Prabhu

Java

5 contributions

Zhilan Wang

Java

5 contributions

Sarah O'Sullivan

Java

5 contributions

Raul Higareda

Java

5 contributions

Utkarsh Prasad

Java

5 contributions

Aashi Tyagi

Java

5 contributions

Chinonso Chinonso

Kotlin

5 contributions

Jongwoo Jeon

Java

4 contributions

Anuprova Bhowmik

Kotlin

Java

4 contributions

Matt Yang

Java

4 contributions

Youngmin Jeon

Java

4 contributions

Akul Gupta

Java

4 contributions

Leo Li

Java

4 contributions

Freddy Platinus

Java

4 contributions

Gargi Balasubramaniam

Java

4 contributions

Saurav Chittal

Java

4 contributions

Hania Dziurdzik

Kotlin

Java

4 contributions

Samuel Schapiro

Java

4 contributions

Charlie Rivera

Java

4 contributions

Arnav Motwani

Kotlin

4 contributions

Ashley Wang

Java

4 contributions

Daniyal Rana

Java

4 contributions

Leena Abdelrahman

Java

4 contributions

Rahul Kalle

Java

4 contributions

Rylan Turner

Java

4 contributions

Larry Liao

Java

4 contributions

Zetai Liu

Java

4 contributions

Aditya Joshi

Java

4 contributions

Prerana Singh

she, her, hers

Full Profile

Java

4 contributions

Dj Figueiredo

Kotlin

4 contributions

Yiming Niu

Java

4 contributions

Milosz Dabrowski

Java

3 contributions

James Rockey

Java

3 contributions

Ojas Upalekar

Java

3 contributions

Bernie Zhu

Java

3 contributions

Jane Liu

Java

3 contributions

Rachel Huang

Java

3 contributions

Ayaan Jabbar

Kotlin

3 contributions

Neel Khare

Java

3 contributions

Violetta Dabros

Java

3 contributions

Palak Purwar

Java

3 contributions

Samarth Taneja

Java

3 contributions

Serena Trika

Java

3 contributions

Yuhua Weng

Java

3 contributions

Apramey Hosahalli

Java

3 contributions

Anish Meka

Java

3 contributions

Aarav Mande

Java

3 contributions

Idrees Mohammed

Kotlin

Java

3 contributions

Daniel Rugutt

Java

3 contributions

Eduardo Martinez

Java

3 contributions

Lina Mei

Kotlin

3 contributions

Serlina Ku

Java

3 contributions

Sana Madhavan

Java

3 contributions

Alyssa Daniels

Java

3 contributions

Preston Chao

Java

3 contributions

Warren Li

Java

3 contributions

Ananya Subramanian

Java

3 contributions

Kushal Agarwal

Java

3 contributions

Zhaoyang Chen

Kotlin

3 contributions

Yu He

Java

3 contributions

David Ruvinskiy

Kotlin

3 contributions

Aditi Khanna

Java

3 contributions

Archna Sobti

Java

3 contributions

Savannah Holly

Java

3 contributions

Anish Thiriveedhi

Java

3 contributions

Joy Wan

Java

3 contributions

Jainil Modi

Java

3 contributions

Vansh Sikka

Java

3 contributions

Vansh Gupta

Java

3 contributions

Will Otani

Java

3 contributions

Havish Rani

Java

3 contributions

Lenna Park

Java

3 contributions

Ananyaa Tanwar

Java

3 contributions

Meghna Mavila

Java

3 contributions

Josh Joseph

Java

3 contributions

Wendy Ruan

Java

3 contributions

Chengze Shen

Java

3 contributions

Nishit Samarth

Java

3 contributions

Becky Blake

Java

3 contributions

Gabriel Grais

Java

3 contributions

Juyoung Choi

Java

3 contributions

Qingping Ye

Java

3 contributions

Kavin Krishnasami

Java

3 contributions

Helen Ilkiu

Java

3 contributions

Athena Fung

Java

3 contributions

Tyler Cushing

Kotlin

3 contributions

David Yang

Java

3 contributions

Di Liang

Java

3 contributions

Andrew Kim

Kotlin

3 contributions

Eric Ji

Java

3 contributions

Chris Munoz

Java

3 contributions

Joseph Dubravec

Java

3 contributions

Meghna Gaddam

Java

3 contributions

Martina Perez Zuleta

Java

3 contributions

Andrew Lum

Java

3 contributions

Jenny Yang

Java

3 contributions

Eunice Leung

Java

3 contributions

Tianyun Zhang

Java

3 contributions

Elisa Carrillo

Java

3 contributions

Louis Qian

Java

3 contributions

Ishq Gupta

Java

3 contributions

Jier Miao

Java

3 contributions

Elijah Song

Kotlin

3 contributions

Bilal Karim

Java

3 contributions

Junhao Xiong

Java

3 contributions

Mick Enev

Java

3 contributions

Matthew McCarthy

Kotlin

3 contributions

Lexi Guan

Java

3 contributions

Ethan Sirois

Kotlin

3 contributions

Alekhya Nathella

Java

2 contributions

Harshit Bagla

Java

2 contributions

Daniel Dilan

Java

2 contributions

Sarod Nori

Java

2 contributions

Samuel Hurh

Java

2 contributions

Ayah Jaber

Java

2 contributions

Adrian Russo

Java

2 contributions

Shao-Min Yeh

Java

2 contributions

Janani Jayanth

Java

2 contributions

Rohan Sathe

Java

2 contributions

Alex Che

Java

2 contributions

Jake Vile

Java

2 contributions

Tanay Pareek

Java

2 contributions

Kangyu Feng

Java

2 contributions

Ken Kim

Java

2 contributions

Brandon Dinh

Java

2 contributions

Ishan Khandelwal

Java

2 contributions

Tina Dou

Java

2 contributions

Emmanuel Buabeng

Java

2 contributions

Yiche Liu

Java

2 contributions

Alma Zirojevic

Java

2 contributions

Anna Fedczuk

Java

2 contributions

Armin Rafieyan

Kotlin

2 contributions

Ricky Chen

Java

2 contributions

Anna Liu

Java

2 contributions

Vaibhav Keshari

Kotlin

2 contributions

Allen Guo

Java

2 contributions

Rahul Bhatt

Java

2 contributions

Brenda Hariyanto

Java

2 contributions

Abhi Vinnakota

Java

2 contributions

Ruozhen Yang

Java

2 contributions

Edmon Guan

Java

2 contributions

Sabrina Tu

Java

2 contributions

Dawn Lim

Kotlin

2 contributions

Joseph Chan

Java

2 contributions

Yasmine Munoz

Java

2 contributions

Tianyi Huang

Java

2 contributions

Cloud Li

Java

2 contributions

Zoe Lu

Java

2 contributions

Srikar Manikonda

Java

2 contributions

Yuan Ochoa

Java

2 contributions

Vish Ganesan

Kotlin

2 contributions

Kelly Chen

Java

2 contributions

Grace Cho

Java

2 contributions

Jared Buabeng

Java

2 contributions

Nathan Liu

Java

2 contributions

Manasi Vaidya

Java

2 contributions

Max Jing

Kotlin

Java

2 contributions

Elizabeth Spencer

Kotlin

2 contributions

Steven Salisbury

Kotlin

2 contributions

Lou Zeh

Java

1 contribution

Juan David Campolargo Hoyos

Java

1 contribution

Ethan Miranda

Kotlin

1 contribution

Mayank Hirani

Java

1 contribution

Aditya Shreenivas Kunte

Java

1 contribution

Siddharth Tangri

Java

1 contribution

Vinayak Manepalli

Java

1 contribution

Varun Shroff

Java

1 contribution

Rohan Khatu

Java

1 contribution

Adrian Rodriguez

Java

1 contribution

Tongyun Huang

Java

1 contribution

Shruthi Jaganathan

Java

1 contribution

Nicholas Jung

Java

1 contribution

Dazhen Chen

Java

1 contribution

Cindy Su

Java

1 contribution

Jason Wu

Java

1 contribution

Jason Barnett

Kotlin

1 contribution

Siyuan Ding

Java

1 contribution

Anish Jampana

Java

1 contribution

Matthew Czech

Java

1 contribution

Aadarsh Krishnan

Java

1 contribution

Raghav Anand

Java

1 contribution

Edward Huang

Java

1 contribution

Meghan Lu

Java

1 contribution

Jimmy Berg

Kotlin

1 contribution

Aryan Vakharia

Java

1 contribution

Connor Flynn

Java

1 contribution

Aaron Taub

Java

1 contribution

Nehal Tangudu

Java

1 contribution

Anisha Raja

Java

1 contribution

Thomas Zelichowski

Java

1 contribution

Blair Wang

Java

1 contribution

Keshav Trikha

Java

1 contribution

Jessica Ho

Java

1 contribution

Hamiz Anjum

Java

1 contribution

Ziyin Wang

Java

1 contribution

Simon Li

Java

1 contribution

Ram Goenka

Java

1 contribution

Ryan Wang

Kotlin

1 contribution

Shoorsen Gandhi

Kotlin

1 contribution

Joe Tamulaitis

Kotlin

1 contribution

Tracy Li

Kotlin

1 contribution

Panyue Chen

Java

1 contribution

Jiaqi He

Java

1 contribution

Yanze Lu

Java

1 contribution

Punn Pinkayan

Java

1 contribution

Jason Cai

Java

1 contribution

Wentao Qi

Java

1 contribution

Ishaan Bhandari

Java

1 contribution

Student Contributors

The following students have contributed explanations to learncs.online, which have been approved by instructors and now appear on the website:

Jorge R.

Java

4 contributions

Ayesha Ahmed

Java

1 contribution

Jo Ma Me

Java

1 contribution

Sisa Pallchisaca

Java

1 contribution

Nathan Chen

Kotlin

1 contribution

Chinasa Nwosu

Java

1 contribution

Michal Lampejo

Java

1 contribution

Aisha Salau

Java

1 contribution

Question Authors

Questions on the lessons and practice page were authored by the following contributors:

Geoffrey Challen

Kotlin

Java

326 questions
(318 Kotlin, 326 Java)

Chris Taylor

Kotlin

Java

35 questions
(2 Kotlin, 35 Java)

Nikita Neledov

Kotlin

Java

1 question
(1 Kotlin, 1 Java)

Ayesha Ahmed

Kotlin

Java

1 question
(1 Kotlin, 1 Java)

Aisha Salau

Kotlin

Java

1 question
(1 Kotlin, 1 Java)

Michal Lampejo

Kotlin

Java

1 question
(1 Kotlin, 1 Java)

CEO

Kotlin

Java

1 question
(1 Kotlin, 1 Java)

Giovanni Pastor

Kotlin

Java

1 question
(1 Kotlin, 1 Java)