3v4l.org

run code in 300+ PHP versions simultaneously
<?php $data = str_repeat('abcde', 500000); $insertion = 'abc'; $position = 0; $data = substr($data, 0, $position) . $insertion . substr($data, $position); echo memory_get_peak_usage(), "\n";

preferences:
115.98 ms | 406 KiB | 5 Q