3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = function () { return null; } echo (int)isset( $foo ); // TRUE because you're testing $foo echo '-'; echo (int)isset( $foo() ); // FALSE because you're testing $foo's response
Output for 5.5.24 - 5.5.30, 5.6.8 - 5.6.16, 7.0.0 - 7.0.1
Parse error: syntax error, unexpected 'echo' (T_ECHO) in /in/iOFA4 on line 4
Process exited with code 255.
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