<?php
$array = array();
$array[0] = "me0";
$array[1] = "me1";
$array[2] = "me2";
$array[4] = "me4";
$array[5] = "me5";
$array[3] = "meChanged";
print_r($array);

?>

Array
(
    [0] => me0
    [1] => me1
    [2] => me2
    [4] => me4
    [5] => me5
    [3] => meChanged
)