php 将两个数组进行相加

数组Array ( [0] => 1 [1] => 2 )和数组Array ( [0] => 5 [1] => 6 ) 怎么让他们想加得出:
数组Array ( [0] => 6 [1] => 8 )

$arr1 = array(1,2,3,4,5);
$arr2 = array(6,7,8,9,10);
$arr = array();
for($i=0,$len=count($arr1); $i<$len; $i++) {
$arr[] = $arr1[$i] + $arr2[$i];
}
print_r($arr);

function add($a,$b) {
return $a + $b;
}
$arr = array_map('add', $arr1, $arr2);
print_r($arr);