Hackerrank Arrays left rotation

rotLeft.php

<?php 

function rotLeft($a, $d) {
    $temp = [];
    for($i = 0; $i < $d; $i++) {
        $temp[$i] = $a[$i];
    }
    $a = array_slice($a, $d);
    $result = array_merge($a, $temp);
    return $result;
}