PHP Cookbook

4.18. Sorting Multiple Arrays

Problem

You want to sort multiple arrays or an array with multiple dimensions.

Solution

Use array_multisort( ) :

To sort multiple arrays simultaneously, pass multiple arrays to array_multisort( ):

$colors = array('Red', 'White', 'Blue');
$cities = array('Boston', 'New York', 'Chicago');

array_multisort($colors, $cities);
print_r($colors);
print_r($cities);
Array
               (
                   [0] => Blue
                   [1] => Red
                   [2] => White
               )
               Array
               (
                   [0] => Chicago
                   [1] => Boston
                   [2] => New York
               )

To sort multiple dimensions within a single array, pass the specific array elements:

$stuff = array('colors' => array('Red', 'White', 'Blue'),
               'cities' => array('Boston', 'New York', 'Chicago'));

array_multisort($stuff['colors'], $stuff['cities']);
print_r($stuff);
Array
               (
                   [colors] => Array
                       (
                           [0] => Blue
                           [1] => Red
                           [2] => White
                       )

                   [cities] => Array
                       (
                           [0] => Chicago
                           [1] => Boston
                           [2] => New York
                       )

               )

To modify the sort type, as in sort( ), pass in SORT_REGULAR, SORT_NUMERIC, or SORT_STRING after the array. To modify the sort order, unlike in sort( ), pass in SORT_ASC or SORT_DESC after the array. You can also pass in both a sort type and a sort order after the array.

Discussion

The array_multisort( ) function can sort several arrays at once or a multidimensional array by one or more dimensions. The arrays are treated as columns of a table to be sorted by rows. The first array is the main one to sort by; all the items in the other arrays are reordered based on the sorted order of the first array. If items ...