Documenting programs

Documentation explains a program. Internal documentation lives inside the code and helps programmers; external documentation, such as a user manual, helps the people who use it. Good documentation makes a program easier to understand, fix and update, even years later.

By the end of this page you can

• Explain why programs need documentation
• Use comments, meaningful names, indentation and white space
• Say what goes in a user manual

Goals tick themselves off as you try the activities below.

Photo: Jonathan Schilling, CC BY-SA 4.0, via Wikimedia Commons. Cropped, resized, JPEG q72.

Comments in the listing tell the next programmer what each part does.