3v4l.org

run code in 300+ PHP versions simultaneously
<?php function test( &$var ) { $var = 'reference'; } $var = 'no reference'; call_user_func('test', $var ); var_dump($var );
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.7
Warning: test(): Argument #1 ($var) must be passed by reference, value given in /in/VW2aB on line 10 string(12) "no reference"
Output for 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
Warning: Parameter 1 to test() expected to be a reference, value given in /in/VW2aB on line 10 string(12) "no reference"
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
string(12) "no reference"
preferences:
250.3 ms | 402 KiB | 400 Q