3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = "a"; $prev = $a; for ($i=0; $i<100000; $i++) { $a++; if (!is_string($a)) { var_dump($prev); var_dump($a); var_dump($i); break; } $prev = $a; } ?>

preferences:
34.34 ms | 402 KiB | 5 Q