Add, delete, and manipulate lines
Add new lines
Normally you press Enter to start a new line when the caret is at the end of that line, but you can also start a new line if the caret is in the middle of a line.
To add a new line below the current line, press Shift+Enter.
To add a new line above the current line, press Ctrl+Alt+Enter.
Join lines
When you need to remove an unnecessary line break and join the next line to the current one, there is no need to place the caret at the end of the line and press Delete. Instead, you can press Ctrl+Shift+J when your caret is anywhere in the first line; this action will also make sure that the resulting line is formatted correctly.
Duplicate lines
Instead of starting an empty line, you can duplicate an existing line and edit it as required.
To duplicate the current line, press Ctrl+D.
Delete current line
One way to delete a line is to select the whole line and press Delete or Backspace, but a slightly more efficient way is to press Ctrl+Y when the caret is anywhere in that line.
Move lines up and down
You can move the line where the caret resides up and down using dedicated shortcuts: Ctrl+Shift+Up and Ctrl+Shift+Down.
If no shortcuts are assigned to these actions in the currently selected keymap, you can assign your own shortcuts to the Move Line Up and Move Line Down actions in the Keymap settings page Ctrl+Alt+S.