array_intersect ( array $array1 , array $array2 [, array $... ] ) : array
<?php
$array1 = array("a" => "green", "red", "blue");
$array2 = array("b" => "green", "yellow", "red");
$result = array_intersect($array1, $array2);
var_dump($result);
/*
array(2) {
["a"]=>
string(5) "green"
[0]=>
string(3) "red"
}
*/
<?php
$array1 = array("a" => "green", "green", "blue");
$array2 = array("b" => "green", "yellow", "red");
$result = array_intersect($array1, $array2);
var_dump($result);
/*
array(2) {
["a"]=>
string(5) "green"
[0]=>
string(5) "green"
}
*/