How to gather code

hello i would to gather the code as here:

a function automatically allows to gather the code (you can see "+" in the left). how can i do this in other ways?

Answer 1

[Ilham Hardy]

Use double percentage signs %% to create a section on your code..

Answer 2

[per isakson]

See

• Code Folding — Expand and Collapse Code Constructs middle of the page and down
• Editor/Debugger Code Folding Preferences bottom of the page