Question

Im trying to organize this kind of array

array
  0 => 
    array
      'id' => '19'
      'nome' => 'Lorem ipsum'
      'order' => '0'
  1 => 
    array
      'id' => '23'
      'nome' => 'Lorem ipsum'
      'order' => '2'
  2 => 
    array
      'id' => '45'
      'nome' => 'Lorem ipsum'
      'order' => '0'
  3 => 
    array
      'id' => '6'
      'nome' => 'Lorem ipsum'
      'order' => '0'
  4 => 
    array
      'id' => '23'
      'nome' => 'Lorem ipsum'
      'order' => '1'
  5 => 
    array
      'id' => '12'
      'nome' => 'Lorem ipsum'
      'order' => '0'

So, I have to put the zeros values in order to the end of the array, and using others order values to ordering correctely the array.

array
  0 => 
    array
      'id' => '23'
      'nome' => 'Lorem ipsum'
      'order' => '1'
  1 => 
    array
      'id' => '23'
      'nome' => 'Lorem ipsum'
      'order' => '2'
  2 => 
    array
      'id' => '19'
      'nome' => 'Lorem ipsum'
      'order' => '0'
  3 => 
    array
      'id' => '45'
      'nome' => 'Lorem ipsum'
      'order' => '0'
  4 => 
    array
      'id' => '6'
      'nome' => 'Lorem ipsum'
      'order' => '0'
  5 => 
    array
      'id' => '12'
      'nome' => 'Lorem ipsum'
      'order' => '0'

I tried using usort like this, with not the correct result:

    usort($items, function() {
        if ($a['uf_order'] == 0) return 0;
        return ($a['uf_order'] > $b['uf_order']) ? -1 : 1;
    });

Answer 1

You have to pass $a and $b in the function:

usort($items, function($a, $b) {
    if ($a['uf_order'] == 0) return 0;
    return ($a['uf_order'] > $b['uf_order']) ? -1 : 1;
});

Also there is no key called uf_order in your array.

As NomikOS correctly stated in his comment. This would only work in PHP 5.3+. If you have an older version of PHP you could do:

usort($items, 'cmp');

function cmp ($a, $b) {
    if ($a['uf_order'] == 0) return 0;
    return ($a['uf_order'] > $b['uf_order']) ? -1 : 1;
}