- var_dump: documentation ( source)
- array_filter: documentation ( source)
- in_array: documentation ( source)
<?php
$data = array(
array("foo" => array()),
array("foo" => array(3,2)),
array("foo" => array(3)),
);
var_dump(array_filter($data, function($value) { return in_array(3,$value['foo']); }));