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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
Kotlin
Java
922 contributions
Colleen Lewis
Kotlin
Java
326 contributions
Chris Taylor
Java
35 contributions
Ellen Spertus
she, her, hers
Teaching Professor, Khoury College of Computer Sciences, Northeastern University
Kotlin
Java
25 contributions

Teacher

Rohith Sanjay
Kotlin
Java
115 contributions
Carlos Inigo Fernandez
Java
41 contributions
Thomas Cai
Kotlin
Java
37 contributions
Conor Cunningham
Java
37 contributions
Miguel Fernandez
Kotlin
Java
30 contributions
Jackie Chan
Kotlin
Java
28 contributions

Tutor

Rachanon Petchoo
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
Ritvik Sood
Java
19 contributions
Patrick Cunningham
Java
18 contributions
Aden Krakman
Java
17 contributions
Ying Chen
Java
17 contributions
Justin Bai
Kotlin
17 contributions
Ruisong Li
Kotlin
Java
16 contributions
Rohan Gudipaty
Java
16 contributions
Hyunho Kim
Kotlin
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
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
Sunwoo Baek
Java
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

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
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
Yanze Lu
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
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
36 questions
(2 Kotlin, 36 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)