3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $x = 10; $foo = null; $ref = &$foo; do { $ref = array('foo' => 'bar'); $ref = &$ref['foo']; } while (--$x); var_dump($foo);
Output for 5.2.1 - 7.2.0
array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> array(1) { ["foo"]=> &string(3) "bar" } } } } } } } } } }
Output for 4.3.0 - 5.2.0
array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &array(1) { ["foo"]=> &string(3) "bar" } } } } } } } } } }