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run code in 300+ PHP versions simultaneously
<?php $str = "Bbbbbbb Bbb\u{00E4}b\u{00E4} Bbbbb\u{00E4}"; var_dump($str); var_dump(strlen($str)); var_dump(substr($str,0,28)); var_dump(['key' => substr($str,0,28)]);
Output for 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
string(24) "Bbbbbbb Bbbäbä Bbbbbä" int(24) string(24) "Bbbbbbb Bbbäbä Bbbbbä" array(1) { ["key"]=> string(24) "Bbbbbbb Bbbäbä Bbbbbä" }

preferences:
111.48 ms | 1521 KiB | 4 Q