& is two tags on one box
Bind $b to $a with &, then pass $a to a function that takes &$list.
<?phpfunction addNine(array &$list): void{ $list[] = 9;}$a = [1, 2];$b = &$a;$b[] = 3;echo 'a: ', implode(',', $a), PHP_EOL;addNine($a);echo 'b: ', implode(',', $b), PHP_EOL;1. Predict the output
Tap the lines in the order you think they print.
- 1…
- 2…