How to reset array keys using PHP

Here is what I want to accomplish:
Original array:

$array[9] = 'Apple';
$array[12] = 'Orange';
$array[5] = 'Peach';

I want to make the above array looks like below:

$array[0] = 'Apple';
$array[1] = 'Orange';
$array[2] = 'Peach';

I just want to re-arrange (reset) the keys in order without changing the order of the array.