- var_dump: documentation ( source)
- array_merge: documentation ( source)
<?php
$k = (string)"0";
$a = array( 'name' => 'a', $k => 'null' );
$b = array( 'name' => 'b', $k => 'zero' );
$c = array( $k => 'zeronull', 'name' => 'c' );
var_dump($a);
var_dump($b);
var_dump($c);
var_dump(array_merge($a, $b));
var_dump(array_merge($a, $c));
var_dump(array_merge($a, $b, $c));