php array_intersect() efficiency

Question

consider the below script. two arrays with only three values.when i compare these two arrays using array_intersect(). the result is fast.

Answer 1

I implementing this simple code of comparing array_intersect and array_intersect_key,

$array = array();
    for( $i=0; $i<130000; $i++)
        $array[$i] = $i;
    for( $i=200000; $i<230000; $i++)
        $array[$i] = $i;
    for( $i=300000; $i<340000; $i++)
        $array[$i] = $i;

    $array2 = array();
    for( $i=100000; $i<110000; $i++)
        $array2[$i] = $i;
    for( $i=90000; $i<100000; $i++)
        $array2[$i] = $i;
    for( $i=110000; $i<290000; $i++)
        $array2[$i] = $i;

    echo 'Intersect to arrays -> array1[' . count($array) . '] : array2[' . count($array2) . '] ' . '
';
    echo date('Y-m-d H:i:s') . '
';
    $time = time();
    $array_r2 = array_intersect_key($array,$array2);
    echo 'Intercept key: ' . (time()-$time) . ' segs
';
    $time = time();
    $array_r = array_intersect($array,$array2);
    echo 'Intercept: ' . (time()-$time) . ' segs
';

the result....

Intersect to arrays -> array1[200000] : array2[200000] 
2014-10-30 08:52:52
Intercept key: 0 segs
Intercept: 4 segs

In this comparing of the efficency between array_intersect and array_intersect_key, we can see the interception with keys it is much faster.