sort an array base on key

Question

i have an array like this:

Array
(
    [0] => Array
        (
            [title] => some title
            [time] => 1279231500
        )

    [1] => Array
        (
            [title] => some title 2
            [time] => 1279231440
        )

    [2] => Array
        (
            [title] => some title 3
            [time] => 1279229880
        )
)

how i can sort it based on time?

score 4 · Accepted Answer · edited Aug 29 '10 at 18:46

4

You can sort it this way (since it is an associative array):

function cmp($a, $b)
{
   return strcmp($a['time'], $b['time']);
}

usort($your_array, "cmp");
print_r($your_array);

edited Aug 29 '10 at 18:46

Peter Ajtai

56,972
13
121
140

answered Aug 29 '10 at 18:24

Sarfraz

377,238
77
533
578

any idea how to reverse the order? – greenbandit Aug 29 '10 at 18:36
@greenbandit - Change the comparison function to `return strcmp($b['time'], $a['time']);` - usort() is sorting based on `cmp()`. – Peter Ajtai Aug 29 '10 at 18:41
@reverse: Either return `-1 * strcmp(...);` or apply `array_reverse` after sort. – NikiC Aug 29 '10 at 18:42
3

You should not use `strcmp` for integer values. Because `2 < 12` but `strcmp(2, 12) === 1` that means “`2` is greater than `12`”. – Gumbo Aug 29 '10 at 19:33

Simon · Answer 2 · 2012-01-20T10:24:43.390

1

As Gumbo mentioned, you should not use strcmp for integer values.

Use this function

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

edited Jan 20 '12 at 10:24

answered Jan 19 '12 at 11:33

Simon

22,637
36
92
121

For integer values, `return $a['time'] - $b['time'];` would suffice. – salathe Jan 19 '12 at 12:19

sort an array base on key

2 Answers2

Linked