Useful shortcuts
You can find all the available shortcuts and change them through the Keymap option in the Settings. If you double-click on the actions, the Edit Shortcuts menu is displayed. From this menu, you can remove the shortcut or add a new one, which can be a keyboard shortcut, a mouse shortcut, or an abbreviation.
Some useful shortcuts for Windows and OS X are included in the following list:
Ctrl + W (Alt + Up arrow on OS X): This selects expressions based on grammar. Press these keys repeatedly to expand the selection. The opposite command is Ctrl + Shift + W (Alt + Up arrow on OS X).
Ctrl + / (Cmd + / on OS X): This comments each line of the selected code. To block comments, use Ctrl + Shift + / (Alt + Cmd + / on OS X).
Ctrl + Alt + I: This indents the selected code. This is useful when cleaning up a block of code or method after you finish writing.
Ctrl + Alt + O: This optimizes the imports, removes the unused imports, and reorders the rest of them.
Shift + Ctrl + Arrows (Alt...