- print_r: documentation ( source)
- array_merge: documentation ( source)
<?php
$a = array();
$a["x"] = "bb";
$a["x"][] = "cc";
print_r($a);
print_r("A");
print_r(empty([]));
print_r("A");
print_r(empty(array()));
print_r("A");
print_r(empty($a));
print_r(array_merge([1,[2,3]],[1]));
?>