To quickly format the code indentation, simply:
1. Select the text to be adjusted.
2. press (control) + (i) .
Animated example of the (control) + (i) hotkey:
The (control) + (i) behaviour is the same as the Editor -> Structure -> Re-Indent selection.
Related Information:
Fix code indentation in Xcode
Xcode Tip: Hotkeys/Shortcuts to move multiple lines horizontally (command ⌘) + ( [ ) or ( ] )
Xcode Tip: Comment Hotkey/Shortcut