up vote 15 down vote favorite
5

I've got the following structue of array:

Array
        (
            [0] => Array
                (
                    [configuration_id] => 10
                    [id] => 1
                    [optionNumber] => 3
                    [optionActive] => 1
                    [lastUpdated] => 2010-03-17 15:44:12
                )

            [1] => Array
                (
                    [configuration_id] => 9
                    [id] => 1
                    [optionNumber] => 2
                    [optionActive] => 1
                    [lastUpdated] => 2010-03-17 15:44:12
                )

            [2] => Array
                (
                    [configuration_id] => 8
                    [id] => 1
                    [optionNumber] => 1
                    [optionActive] => 1
                    [lastUpdated] => 2010-03-17 15:44:12
                )
    )

What's the best way for order the array, in an incremental way based on the optionNumber?

So the results look like:

Array
        (
            [0] => Array
                (
                    [configuration_id] => 8
                    [id] => 1
                    [optionNumber] => 1
                    [optionActive] => 1
                    [lastUpdated] => 2010-03-17 15:44:12
                )

            [1] => Array
                (
                    [configuration_id] => 9
                    [id] => 1
                    [optionNumber] => 2
                    [optionActive] => 1
                    [lastUpdated] => 2010-03-17 15:44:12
                )

            [2] => Array
                (
                    [configuration_id] => 10
                    [id] => 1
                    [optionNumber] => 3
                    [optionActive] => 1
                    [lastUpdated] => 2010-03-17 15:44:12
                )
    )
share|improve this question

3 Answers

up vote 31 down vote accepted

Use usort.

function cmp_by_optionNumber($a, $b) {
  return $a["optionNumber"] - $b["optionNumber"];
}

...

usort($array, "cmp_by_optionNumber");
share|improve this answer
That doesn't really helpe me as usort requires I provide it a function to use - which is the difficult bit I can't get my head round – Sjwdavies Mar 19 '10 at 13:15
1  
Well he just gave you the function to use. And you're going to have to accept that there's not always a built-in function to do what you want, you have to write it yourself. Comparison functions just require a return of 1, 0, or -1 indicating the sort order for two elements. – Tesserex Mar 19 '10 at 13:19
I looked further into usort and it is actually quite cool. I wrote a simple comparison function to the one above, however missed out the '=='. Thanks for the help guys – Sjwdavies Mar 19 '10 at 13:38
+1: exactly what I wanted, thanks! – OneThreeSeven Apr 6 '12 at 15:48
up vote 18 down vote

Use usort

 usort($array, 'sortByOption');
 function sortByOption($a, $b) {
   return strcmp($a['optionNumber'], $b['optionNumber']);
 }
share|improve this answer
This one worked for me. @KennyTM's didn't seem to work – Ben Sinclair Jun 15 '12 at 3:35
@BenSinclair, that's because Kenny's solution is for numbers, this solution is for strings. They are both correct :-) +1 for this alternative. – confeng Jan 29 at 19:34
up vote 0 down vote

The keys are removed when using a function like the ones above. If the keys are important, the following function would maintain it... but foreach loops are pretty inefficient.

function subval_sort($a,$subkey) {
    foreach($a as $k=>$v) {
        $b[$k] = strtolower($v[$subkey]);
    }
    asort($b);
    foreach($b as $key=>$val) {
        $c[$key] = $a[$key];
    }
    return $c;
}
$array = subval_sort($array,'optionNumber');

Use arsort instead of asort if you want from high to low.

Code credit: http://www.firsttube.com/read/sorting-a-multi-dimensional-array-with-php/

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.