Move array item with certain key to the first posi

Question

What's the most elegant way in PHP to move an array element chosen by key to the first position?

Input:

$arr[0]=0;
$arr[1]=1;
$arr[2]=2;
....
$arr[n]=n;
$key=10;

Output:

$arr[0]=10;
$arr[1]=0;
$arr[2]=1;
$arr[3]=2;
....
$arr[n]=n;

Answer 1

<?php
$key = 10;
$arr = array(0,1,2,3);
array_unshift($arr,$key);
var_dump($arr) //10,0,1,2,3
?>

Answer 2

$tgt = 10;
$key = array_search($tgt, $arr);
for($i=0;$i<$key;$i++)
{
   $temp = $arr[$i];
   $arr[$i] = $tgt;
   $tgt = $temp;
}

After this simple code, all you need to do is display the re-arranged array. :)