3v4l.org

run code in 300+ PHP versions simultaneously
<?php $chars = "\xE4"; setlocale(LC_CTYPE, "de_DE", "de", "german", "ge", "de_DE.ISO8859-1", "ISO8859-1"); print_r($chars); print_r(strtoupper($chars)); echo strcasecmp($chars, strtoupper($chars))."\n";

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58.41 ms | 402 KiB | 5 Q