3v4l.org

run code in 300+ PHP versions simultaneously
<?php $key = md5(""); $i = 0; $str = ""; while ($i < strlen($key)) { if (strpos($str, $key[$i]) === false) { $str .= $key[$i]; } $i++; } echo $str;

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50.51 ms | 402 KiB | 5 Q