3v4l.org

run code in 300+ PHP versions simultaneously
<?php $data = ['foo'=>'1', 'bar'=>'2', 'baz'=>'3']; while(list($key, $value) = each($data)) { echo(sprontf('Current key is [%s] and value [%s]'.PHP_EOL, $key, $value)); if($value==='2') { end($data); $result = key($data); } }

preferences:
36.46 ms | 402 KiB | 5 Q