php Array usort

gistfile1.txt

$array = array(
  array('key' => 'key', 'value' => 1),
  array('key' => 'bey', 'value' => 1),
  array('key' => 'zey', 'value' => 1),
  array('key' => 'aey', 'value' => 1)
);
        
uasort($array, 
  function($a, $b) 
  {
      return strcmp($a['key'], $b['key']);
  }
);