3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 'foo'; $b = &$a; (unset)$b; var_dump($a, $b);
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Fatal error: The (unset) cast is no longer supported in /in/8uupK on line 5
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.25, 7.4.27 - 7.4.33
Deprecated: The (unset) cast is deprecated in /in/8uupK on line 5 string(3) "foo" string(3) "foo"
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 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.3.32 - 7.3.33, 7.4.26
string(3) "foo" string(3) "foo"
preferences:
273.51 ms | 404 KiB | 388 Q