3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(true => true,false => false,);var_dump($a, array_key_exists(true, $a));
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(2) { [1]=> bool(true) [0]=> bool(false) } bool(true)
Output for 4.3.2 - 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, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
Warning: array_key_exists(): The first argument should be either a string or an integer in /in/9YtYq on line 2 array(2) { [1]=> bool(true) [0]=> bool(false) } bool(false)
Output for 4.3.0 - 4.3.1
Warning: array_key_exists() [http://www.php.net/function.array-key-exists]: The first argument should be either a string or an integer in /in/9YtYq on line 2 array(0) { } bool(false)

preferences:
255.88 ms | 402 KiB | 326 Q