3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array( 'one' => 1, 'two' => 2, 'three' => '0', 'four' => null, 'five' => '' ); var_dump(isset($a['three'])); var_dump(empty($a['three'])); var_dump(isset($a['four'])); var_dump(empty($a['four'])); var_dump(isset($a['five'])); var_dump(empty($a['five']));
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
bool(true) bool(true) bool(false) bool(true) bool(true) bool(true)
preferences:
248.83 ms | 406 KiB | 354 Q