在特定键上对多维数组排序

Question

I have an array that loops through a set of a values, this is how it looks:

$arr[] = array("name" => $name, 
               "add1" => $add1, 
               "add2" => $add2, 
               "add3" => $add3, 
             "postcode" => $pc, 
       "distance" => $distance);

Simple and quick question (although I'm struggling with the answer), I was wondering how I can sort the array into distance ascending (which is a floating number) order?

Answer 1

You can use usort and compare the distance in your comparison function:

usort($arr, function($a, $b){
    return $a['distance'] - $b['distance'];
});

Answer 2

Edit :

I think I understand what it is you want to achieve now. Try this:

function array_sort_by_column(&$array, $col, $direction = SORT_ASC) {
    $sort_col = array();

    foreach ($array as $key => $row) {
        $sort_col[$key] = $row[$col];
    }

    array_multisort($sort_col, $direction, $array);
}

array_sort_by_column($arr, 'distance');

Answer 3

An alternative that I've found to organize my arrays is putting them as key, and then organizing with these keys.

Example (using your code):

$arr = array();    
$arr[$distance] = array("name" => $name, 
                   "add1" => $add1, 
                   "add2" => $add2, 
                   "add3" => $add3, 
                 "postcode" => $pc, 
           "distance" => $distance);

ksort($arr);

Answer 4

You can use the usort for sorting an array on personalized rules

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

    usort($array, "sortOnDistance");
?>