Write code. Right now.
Coders Rock
16 short challenges that run in your browser -- pseudocode, Python, JavaScript, Java, C++, and C#. No account. No streaks. No leaderboard. Practice a concept, see it run, then go build something real with it.
Press Run to see what your code does.
How this works
Three steps, then you leave
Learn to Write Code is the school. Coders Rock is the workshop. The goal is not to keep you here.
A lesson on Learn to Write Code explains one idea, in plain English first and then in six languages.
Come here and type it yourself. Short challenges, real output, and an answer waiting if you get stuck.
Once a concept sticks, close the tab and use it. That is the whole point, and nothing here is designed to stop you.
Challenge sets
Follow the curriculum, or jump in anywhere
Each set practices one lesson. They are in curriculum order, but nothing is locked.
Variables & Data
Store a value, change it, and show it.
02Operators & Comparisons
Do arithmetic, and ask questions that answer true or false.
03Input, Output & Comments
Ask a question, use the answer, and leave a note for the next reader.
04Program Structure & Sequence
Order matters -- run the steps in the order the result needs.
05Conditions & Branching
Let the program choose between two or more paths.
06Loops & Repetition
Repeat work without writing it out over and over.
07Functions & Reuse
Write something once and use it as many times as you like.
08Objects & Blueprints
Describe a thing once, then make as many of them as you need.