Welcome to CSE 121: Introduction to Computer Programming πŸŽ‰

What is this class? What will I learn?

Computing continues to play an ever-increasing role in today’s society. Having an understanding of computing is an essential skill for those in the 21st century; from working in industries more reliant on technology, using computational methods to further scientific understanding, or being an informed citizen in a world with technology all around us.

This course is a first course in computer programming focused on the basics of procedural programming in Java. It assumes students have not taken a previous programming course and do not have substantial other programming experience. (Students with previous experience are encouraged to consider CSE 122.)

Prior Experience and Expectations

Prerequisite Material

To better assess if CSE 121 is the right class for you, the Allen School has developed a Self-Guided Placement to help students assess which intro course is the right one for them to enroll in. Please see this website for more information on who to contact if you have questions about which introductory CSE course is the right course for you.

Programming Language

CSE 121 is taught in the Java programming language. No prior experience in Java is required!


If you want to learn more about the course and its policies, please check out our course syllabus.


Feedback is always welcome! You can contact the the course staff or submit anonymous feedback.


Please do not email the course staff or instructors regarding registration for the course. The course staff do not have access to add codes. Please email ugrad-adviser@cs.washington.edu for assistance.


This Week (at a glance)

Monday (12/04)

  • Nothing!

Tuesday (12/05)

  • πŸ§‘β€πŸ« Section 16: Array Patterns

Wednesday (12/06)

  • πŸ‘₯ Lesson 17: Final Exam Review
    A lecture @ 11:30 in KNE 130; B lecture at 3:30 in KNE 120

Thursday (12/07)

Friday (12/08)

  • πŸ‘₯ Lesson 18: Wrap-Up; Victory Lap!
    A lecture @ 11:30 in KNE 130; B lecture at 3:30 in KNE 120

Saturday (12/09)

  • Nothing!

Sunday (12/10)

  • Nothing!



This is a rough sketch of the quarter and things are subject to change. We can accurately predict the past, but predicting the future is hard!


Anything listed in the “Lesson” materials for a day should be read before attending class that day. The Lessons are a first introduction to the most important terms and concepts for that day of class. It is okay if the Lesson doesn’t make complete sense as we have the rest of the class day to clarify the concepts, but if you don’t do the Lesson the class session won’t make any sense.

Topic Programming / Creative Projects Resubmissions
Week 0
Mon 09/25
Tue 09/26 No class
Wed 09/27
LES 00 Welcome!; Course Policies

Note: Normally you would complete the Pre-class Work before class. There is nothing you need to complete before class today!

Thu 09/28
SEC 00 Welcome!
resources: materials
Fri 09/29
LES 01 Printing; Turtle Basics
I.S. by 11:59pm PT
Week 1
Mon 10/02
Tue 10/03
SEC 01 Printing; Turtle Basics
resources: materials
Wed 10/04
LES 02 Datatypes; Expressions
I.S. by 11:59pm PT
Thu 10/05
SEC 02 Datatypes; Expressions
resources: materials
Fri 10/06
LES 03 Variables; Strings; Debugging
Week 2
Mon 10/09
Tue 10/10
SEC 03 Variables; Strings; Debugging
resources: materials
Wed 10/11
LES 04 for Loops
I.S. by 11:59pm PT
Thu 10/12
SEC 04 For Loops
resources: materials
C0, P0 Due 11:59pm PT
Fri 10/13
LES 05 Nested for Loops; Random; Math
Week 3
Mon 10/16
Tue 10/17
SEC 05 Nested For Loops; Random; Math
resources: materials
Wed 10/18
LES 06 Methods; Scope
I.S. by 11:59pm PT
Thu 10/19
QUIZ 00 Quiz 0: Printing, Datatypes, Expressions, for Loops
C0, P0, C1 Due 11:59pm PT
Fri 10/20
LES 07 Parameters
Week 4
Mon 10/23
Tue 10/24
SEC 07 Methods; Parameters
resources: materials
Wed 10/25
LES 08 Return Values
I.S. by 11:59pm PT
Thu 10/26
SEC 08 Return Values
resources: materials
C0, P0, C1, P1 Due 11:59pm PT
Fri 10/27
LES 09 Conditionals
Week 5
Mon 10/30
Tue 10/31
SEC 09 Conditionals
resources: materials
Wed 11/01
LES 10 while Loops
Thu 11/02
QUIZ 01 Quiz 1: Nested for Loops, Random, Math, Methods, Parameters, Return Values
P0, C1, P1, C2 Due 11:59pm PT
Fri 11/03
LES 11 User Input (Scanner)
I.S. by 11:59pm PT
Week 6
Mon 11/06
Tue 11/07
SEC 11 while Loops; User Input (Scanner)
resources: materials
Wed 11/08
LES 12 Putting It All Together

Note: No Pre-Class Material for Today!

Thu 11/09
SEC 12 Putting It All Together
resources: materials
C1, P1, C2, P2 Due 11:59pm PT
Fri 11/10
HOLIDAY Veterans' Day (observed)
Week 7
Mon 11/13
Tue 11/14
SEC 13 Quiz Review / Prep
Wed 11/15
LES 13 Arrays
I.S. by 11:59pm PT
Thu 11/16
QUIZ 02 Quiz 2: Conditionals, while Loops, User Input (Scanner)
P1, C2, P2, C3 Due 11:59pm PT
Fri 11/17
LES 14 Reference Semantics
Week 8
Mon 11/20
Tue 11/21
HOLIDAY Cancelled
Wed 11/22
LES 14.5 Optional Lecture!
Thu 11/23
HOLIDAY Thanksgiving
Fri 11/24
HOLIDAY Native American Heritage Day (observed)
Week 9
Mon 11/27
Tue 11/28
SEC 14 Arrays; Reference Semantics
resources: materials
Wed 11/29
LES 15 2D Arrays
I.S. by 11:59pm PT
Thu 11/30
SEC 15 2D Arrays
resources: materials
C2, P2, C3 Due 11:59pm PT
Fri 12/01
LES 16 Array Patterns
Week 10
Mon 12/04
Tue 12/05
SEC 16 Array Patterns
resources: materials
Wed 12/06
LES 17 Final Exam Review

Note: No Pre-Class Material for Today!

Thu 12/07
SEC 17 Final Exam Review; Wrap-Up
resources: materials
all assignments Due 11:59pm PT
Fri 12/08
LES 18 Wrap-Up; Victory Lap!

Note: No Pre-Class Material for Today!

Week 11
Mon 12/11 Finals Week
Tue 12/12 Finals Week
Wed 12/13
EXAM Final Exam 12:30pm - 2:20pm
Thu 12/14 Finals Week
Fri 12/15 Finals Week