 <p>As @PinkElephantsOnParade writes, it makes no difference for the execution. Thus, it's solely a matter of personal aesthetical preference.</p> <p>I myself set my editor to display trailing whitespace, since I think trailing whitespace is a bad idea. Thus, your line 10 would be highlighted and stare me in the face all the time. Nobody wants that, so I'd argue line 10 should not contain whitespace. (Which, coincidentally is how my editor, emacs, handles this automatically.)</p>