PHP数组排序

Question:

Array
(
    [1257984000] => 2009-11-11 19:00:00
    [1258416000] => 2009-11-16 19:00:00
    [1258722000] => 2009-11-20 08:00:00
    [1258394400] => 2009-11-16 13:00:00
)

This is my array. I want to sort based on the array number( ie. 1257984000,1258416000 etc).

Coding Used:

function cmp($a, $b) {
   if ($a == $b) {
     return 0;
   }
  return ($a < $b) ? -1 : 1;
}
uasort($array, 'cmp');

It is not sorting properly. Whether my coding style is correct? Please help me to solve this issue.

Thanks.

Use ksort to sort by key.