- var_dump: documentation ( source)
- in_array: documentation ( source)
<?php
$a = ['a'];
function &set_a($value) {
static $a = [];
if (!in_array($value, $a, TRUE)) {
$a[] = $value;
}
return $a;
}
$a = &set_a('a');
foreach ($a as &$value) {
var_dump($value);
set_a('b');
}