3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $false = null; $test = array(); $test['parent'] = array(); $test['parent']['child'] = 'foo'; $test['parent'][$false] = 'bar'; var_dump(isset($test['parent']['child'])); var_dump(isset($test['parent'][$false])); var_dump($test);
Output for 4.3.0 - 7.2.0
bool(true) bool(true) array(1) { ["parent"]=> array(2) { ["child"]=> string(3) "foo" [""]=> string(3) "bar" } }