sorting by value in a multidimensional array

Question

This is a multidimensional array I got from Google Calendar for displaying events.

Array
(
[items] => Array
    (
        [0] => Array
            (
                [status] => confirmed
                [summary] => Let's go swimming!
                [start] => Array
                    (
                        [dateTime] => 2011-12-30T09:00:00-05:00
                    )

                [end] => Array
                    (
                        [dateTime] => 2011-12-30T10:00:00-05:00
                    )

            )

        [1] => Array
            (
                [status] => confirmed
                [summary] => red wine
                [start] => Array
                    (
                        [dateTime] => 2011-12-28T06:00:00-05:00
                    )

                [end] => Array
                    (
                        [dateTime] => 2011-12-28T07:00:00-05:00
                    )

            )

        [2] => Array
            (
                [status] => confirmed
                [summary] => Christmas
                [start] => Array
                    (
                        [dateTime] => 2011-12-28T09:30:00-05:00
                    )

                [end] => Array
                    (
                        [dateTime] => 2011-12-28T10:30:00-05:00
                    )

            )
     )
)

I want to use PHP to sort by end[datetime]. If anyone could give me some help I would really appreciate it. I was wondering how to do it.

Duplicate of http://stackoverflow.com/questions/2699086/php-sort-multidimensional-array-by-value? — liquorvicar, Dec 28 '11 at 19:10

score 9 · Accepted Answer · answered Dec 28 '11 at 19:10

9

usort($array['items'], function($a, $b){
    if ($a['end']['dateTime'] === $b['end']['dateTime']) return 0;
    else return ($a['end']['dateTime']  > $b['end']['dateTime']) ? -1 : 1;
});

usort();

In this particular case you can compare the dates as strings and get the correct answer due to the format. In some other cases, you might need other methods, like converting to unix timestamp and comparing those.

answered Dec 28 '11 at 19:10

goat

31,486
7
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I used an anonymous function, which needs php 5.3+. See the example in the manual for other ways to specify the comparison function. – goat Dec 28 '11 at 20:05
yep, works after I separated the function and called it by `usort($response['items'], 'function_name');`, thanks! – Ryan Koehler Dec 28 '11 at 20:28
*...well this changes everything...* – d-_-b Jun 09 '14 at 22:59

score 0 · Answer 2 · answered Dec 28 '11 at 19:11

0

AFAIK there is no direct way to to that. I typically do something like

$items=array();
foreach($mainarray['items'] as $k=>$v) $items[$v['end']['$dateTime'."-$k"]]=$v;
ksort($items);
$mainarray['items']=array_values($items);

answered Dec 28 '11 at 19:11

Eugen Rieck

64,175
10
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sorting by value in a multidimensional array

2 Answers2