3v4l.org

run code in 300+ PHP versions simultaneously
<?php echo isset('');
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.24, 8.2.0 - 8.2.11
Fatal error: Cannot use isset() on the result of an expression (you can use "null !== expression" instead) in /in/bOkXS on line 3
Process exited with code 255.
Output for 5.4.0 - 5.4.45
Parse error: syntax error, unexpected '''' (T_CONSTANT_ENCAPSED_STRING) in /in/bOkXS on line 3
Process exited with code 255.

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