- var_dump: documentation ( source)
- array_intersect_key: documentation ( source)
- array_flip: documentation ( source)
<?php
$foo = ['foo', 'bar', 'red'];
$bar = ['foo' => 'foo', 'bar' => 'bar', 'green' => 'green'];
var_dump(array_intersect_key(array_flip($foo), $bar));