- var_dump: documentation ( source)
- array_diff: documentation ( source)
<?php
$aa = [
'schemas', 'id', 'externalId', 'meta', 'userName', 'active', 'emails', 'orgname', 'department', 'roles', 'address', 'phoneNumbers'
];
$attributes = ['schemas', 'id', 'externalId', 'kllsdaf'];
$re = array_diff($attributes, $aa);
var_dump($re);