3v4l.org

run code in 300+ PHP versions simultaneously
<?php $foo = substr("foo",3); if($foo !== FALSE){ echo "PHP 7\n"; echo gettype($foo); //string } else{ echo "PHP 5\n"; echo gettype($foo); //boolean }
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.29, 8.2.0 - 8.2.20, 8.3.0 - 8.3.8
PHP 7 string

preferences:
139.54 ms | 404 KiB | 175 Q