3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array('foo' => null); var_export($array); echo "\nisset? "; var_export(isset($array['foo'])); echo "\narray_key_exists? "; var_export(array_key_exists('foo', $array)); echo "\n";

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38.85 ms | 402 KiB | 5 Q