There's not two situations. The expression $a || $b evaluates to either $a's value if it has a not-false value (for the normal plethora of false values), othewise $b's value is used. What may happen in some cases is that expression's value is then used in a boolean context where it's further evaluated as true/false (e.g. if( $a || $b ) { ... }), but that's not really relevant in your example since print isn't going to impose a boolean context.