Let's suppose you're making changes to your code in emacs and... now your code indentation is all out of whack. It would be too laborious to re-do the indentation manually.
Rest assured, you can easily have the whole file automatically re-indented in emacs, as described in a StackExchange question (see reference 1).
The command for this is first to select the entire file, then to tell it to re-indent the region, as follows:
Select the entire file:
ctrl-x h
Re-do the auto-indentation:
alt-x indent-region
The correct Emacs terminology is M-x indent-region, but I've called it alt-x here because that's the exact keys I would press on a PC keyboard.
Cited sources:
1. Can I have emacs automatically indent my whole code after it is all written? Stack Exchange.
