3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array('l' => foo); var_dump(isset($a[null])); var_dump(isset($a['4'])); var_dump(isset($a['l']));
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Fatal error: Uncaught Error: Undefined constant "foo" in /in/r3fJ0:3 Stack trace: #0 {main} thrown in /in/r3fJ0 on line 3
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.33
Warning: Use of undefined constant foo - assumed 'foo' (this will throw an Error in a future version of PHP) in /in/r3fJ0 on line 3 bool(false) bool(false) bool(true)
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, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20
Notice: Use of undefined constant foo - assumed 'foo' in /in/r3fJ0 on line 3 bool(false) bool(false) bool(true)

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