Best way to sort an array depending on a subvalue

Question

I have an array created like that :

$myarray = array();
$myarray['id1'] = array('pos' => 3, 'data' => '...');
$myarray['id2'] = array('pos' => 1, 'data' => '...');
$myarray['id3'] = array('pos' => 2, 'data' => '...');

I would like to iterate on $myarray with the order of the pos value. How can I do that ?

The only way I see for the moment is recreate a new ordered array from the first one. That's ugly, of course...

EDIT: This is not a duplicate of this question. I want to keep the keys linked to my subarrays.

Yes, recreate a new array from the first one. That's ugly. Why downvoting ? — Caduchon, Jun 07 '15 at 14:11
Duplicate... maybe. But reading the doc, the solution of the other question is not appropriate to this case. — Caduchon, Jun 07 '15 at 14:22
Read this: http://stackoverflow.com/q/17364127/3933332 <- And your solution is in there — Rizier123, Jun 07 '15 at 14:32

score 3 · Accepted Answer · answered Jun 07 '15 at 14:07

3

You can use uasort http://php.net/manual/en/function.uasort.php

to define custom sort functions:

uasort($myarray, "mySortFunction");

function mySortFunction($a, $b){
  return $a["pos"] - $b["pos"]; //or $b - $a, depending on desired order
}

answered Jun 07 '15 at 14:07

dognose

20,360
9
61
107

score 2 · Answer 2 · answered Jun 07 '15 at 14:07

2

You can use uasort to save keys

$myarray['id1'] = array('pos' => 3, 'data' => '...');
$myarray['id2'] = array('pos' => 1, 'data' => '...');
$myarray['id3'] = array('pos' => 2, 'data' => '...');

uasort ($myarray, function($it1, $it2) { return $it1['pos'] - $it2['pos']; });
var_dump($myarray);

array(3) {
  ["id2"]=>
  array(2) {
    ["pos"]=>
    int(1)
    ["data"]=>
    string(3) "..."
  }
  ["id3"]=>
  array(2) {
    ["pos"]=>
    int(2)
    ["data"]=>
    string(3) "..."
  }
  ["id1"]=>
  array(2) {
    ["pos"]=>
    int(3)
    ["data"]=>
    string(3) "..."
  }
}

answered Jun 07 '15 at 14:07

splash58

26,043
3
22
34

This solution is very nice. I would like to accept it, but it doesn't work on one of my workstations with a too old version of php (5.2.17). The solution of dognose is more general. – Caduchon Jun 07 '15 at 18:07
@Caduchon No problem :) Moreover, it is the same – splash58 Jun 07 '15 at 19:10

Best way to sort an array depending on a subvalue

2 Answers2