3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array("person1" => array(0 => array('k1'=>'v1', 'k2'=>'v2'), 1 => array('k1'=>'v1', 'k2'=>'v2')), "person2" => array(0 => array('k1'=>'v1', 'k2'=>'v2'), 1 => array('k1'=>'v1', 'k2'=>'v2'))); $reset = reset($array); echo $reset[0]['k1']; print_r(array_flip($reset[0]));

preferences:
36.88 ms | 402 KiB | 5 Q