Php sort an object by two criteria?

Question

Trying to sort this array of objects by depth (1) and (2) by weight, and I'm not sure how to change the function I use to enable this other level ...

I am using this function:

function cmp( $a, $b ) { if( $a->weight == $b->weight ){ return 0 ; } return ($a->weight < $b->weight) ? -1 : 1; } 

And then do the following:

 $menu = get_tree(4, $tid, -1, 2); usort($menu, 'cmp'); 

And it exactly sorts the array by weight, but I need to add another sorting level. So the array is first sorted by depth, and then by weight.

So, if the original array looks like this:

  Array ( [0] => stdClass Object ( [tid] => 24 [name] => Sample [weight] => 3 [depth] => 0 ) [1] => stdClass Object ( [tid] => 66 [name] => Sample Subcategory [weight] => 0 [depth] => 1 ) [2] => stdClass Object ( [tid] => 67 [name] => Another Example [weight] => 1 [depth] => 0 ) [3] => stdClass Object ( [tid] => 68 [name] => Subcategory for Another Example [weight] => 1 [depth] => 1 ) [4] => stdClass Object ( [tid] => 22 [name] => A third example master category [weight] => 0 [depth] => 0 ) 

I can sort it first by depth, then by weight, so that the result looks like this:

 Array ( [0] => stdClass Object ( [tid] => 22 [name] => A third example master category [weight] => 0 [depth] => 0 ) [1] => stdClass Object ( [tid] => 67 [name] => Another Example [weight] => 1 [depth] => 0 ) [2] => stdClass Object ( [tid] => 24 [name] => Sample [weight] => 3 [depth] => 0 ) [3] => stdClass Object ( [tid] => 66 [name] => Sample Subcategory [weight] => 0 [depth] => 1 ) [4] => stdClass Object ( [tid] => 68 [name] => Subcategory for Another Example [weight] => 0 [depth] => 1 ) 

Answer 1

 function cmp( $a, $b ) { if ($a->depth == $b->depth) { if($a->weight == $b->weight) return 0 ; return ($a->weight < $b->weight) ? -1 : 1; } else return ($a->depth < $b->depth) ? -1 : 1; } 

Answer 2

when comparing numbers you can just subtract them

 function cmp($a, $b) { $d = $a->depth - $b->depth; return $d ? $d : $a->weight - $b->weight; }