Free CS curriculum · Free forever

Learn to code for a software engineering role.

Start with a free computer-science curriculum written as readable walkthroughs, then keep the cheatsheets open beside you as you build.

Explore the platform

hackuniversity.dev/dashboard/learn/intro-to-computer-science/1-2

1/27 lessons4%

1. What a Program Is

✓Computers follow instructions

✓Run your first line of Python

✓Programs take input

✓Read the error, fix the bug

Lesson 1-2 · 10 min

Run your first line of Python

This is a whole program. One line, and it produces one line of output.

1print("Hello, world!")

Output

Hello, world!

Lesson 1-3 · 10 min

Programs take input

Change the input and the output changes with it. The instructions stayed identical.

1print("You typed:", input())

Output

You typed: hi there

Mark lesson complete✓ Completed

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Learn

A free coding curriculum for beginners and self-taught programmers.

If you are asking how to learn to code, start with a computer-science path that explains every idea in plain English, taking you from your first program to writing real software with confidence.

Every lesson is a walkthrough you read: worked examples, diagrams, and the reasoning behind each step. No account, no sign-up, and your place is remembered in your browser as you go.

Browse the curriculum

hackuniversity.dev/dashboard/learn/intro-to-computer-science/1-2

1/27 lessons4%

1. What a Program Is

✓Computers follow instructions

✓Run your first line of Python

✓Programs take input

✓Read the error, fix the bug

Lesson 1-2 · 10 min

Run your first line of Python

This is a whole program. One line, and it produces one line of output.

1print("Hello, world!")

Output

Hello, world!

Lesson 1-3 · 10 min

Programs take input

Change the input and the output changes with it. The instructions stayed identical.

1print("You typed:", input())

Output

You typed: hi there

Mark lesson complete✓ Completed

← PrevOutlineNext →

Reference

Quick references for the tools you will actually use at work.

Sixty-five cheatsheets across languages, web, backend, networking, graphics, data, cloud, devops, testing, and tooling. Each one is a reference, not a tutorial, so you can find the exact syntax fast.

Sections are anchored and linkable, every code block has a copy button, and the whole library is open to everyone with no limits.

Open the cheatsheets

hackuniversity.dev/cheatsheets/python/strings

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