How to get common values from two different arrays in PHP [closed]

I have two arrays with some user-id

$array1 = array("5","26","38","42");

$array2 = array("15","36","38","42");

What I need is, I need the common values from the array as follows

$array3 = array(0=>"38", 1=>"42");

I have tried array_intersect(). I would like to get a method that takes a minimum time of execution. Please help me, friends.

Native PHP functions are faster than trying to build your own algorithm.

$result = array_intersect($array1, $array2);

Use this one, though this maybe a long method:

$array1 = array("5","26","38","42");

$array2 = array("15","36","38","42");

$final_array = array();

foreach($array1 as $key=>$val){
    if(in_array($val,$array2)){
        $final_array[] = $val;
    }
}

print_r($final_array);

Result: Array ( [0] => 38 [1] => 42 )