3v4l.org

run code in 500+ PHP versions simultaneously
<?php function & retRef() { global $foo; return $foo; } // don't assign by reference doesn't result in a reference $foo = 'init'; $bar = retRef(); $bar = 'bar'; var_dump($foo, $bar); // reset variables unset($foo, $bar); // requires to assign the function call by reference $foo = 'init'; $bar = & retRef(); $bar = 'bar'; var_dump($foo, $bar);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 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 - 8.1.34, 8.2.0 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11
string(4) "init" string(3) "bar" string(3) "bar" string(3) "bar"

preferences:
35.36 ms | 1138 KiB | 7 Q