Write and run your first program

You do not need to set anything up. Open the editor, choose a language, and what you write runs on our machines rather than yours, which is the whole point of it being in a browser.

Run something

1. Choose your language. The editor changes to suit it, and starts you with a small working program.
2. Change it, or replace it with your own.
3. Run it. Output appears below the editor.

The starting program is there so that your first run works. Running it before you change anything tells you the language is doing what you expect, which is worth knowing before you go looking for a mistake in your own code.

Giving your program input

Plenty of programs read something before they can do anything. There are two ways to give them that.

• Input

  Type what your program should read, before you run it. The program reads it as though somebody had typed it.

  Good for the same input over and over while you are fixing something.

• Interactive

  Run the program and answer it as it asks, the way you would in a terminal.

  Good for programs that ask questions, and for seeing what a person using it would see.

Trying another language

Switching language does not change how anything works. The editor, running, input and output all behave the same way, which makes trying a language you do not know a much smaller step than installing one.

What next

Anything worth coming back to needs saving, and that is what a project is.

The IDE covers the editor itself in full, and there is a mobile app if you would rather work on a phone.