Online PHP editor | refs for vLG09

<?php $array = [ ['id' => 1, 'sort_code' => 4], ['id' => 2, 'sort_code' => 2], ['id' => 3], ['id' => 4, 'sort_code' => 8], ['id' => 5], ['id' => 6, 'sort_code' => 6] ]; uasort($array, function($a, $b) { echo "\n" . json_encode($a) . " -vs- " . json_encode($b) . " eval: "; echo $eval = (int)(isset($a['sort_code'], $b['sort_code']) && $a['sort_code'] > $b['sort_code']); return $eval; }); echo "\n---\n"; var_export($array); echo "\n======\n"; uasort($array, function($a, $b) { echo "\n" . json_encode($a) . " -vs- " . json_encode($b) . " eval: "; echo $eval = ($a['sort_code'] ?? 0) <=> ($b['sort_code'] ?? 0); return $eval; }); echo "\n---\n"; var_export($array);