When closing an unsaved file in a code editor, for example Sublime or VS Code, you will see this dialog:
I know I can hit
ENTER to save it, or hit
ESC to cancel it, but how do I use keyboard to select “Don’t Save”?
Here is the solution, go to
System Preference -> Keyboard -> Shortcuts and check
Then you can use
SPACE to select “Don’t Save”. (Notice the focus cue on the button)