Online PHP editor | refs for 3BUJe

<?php function x($value, $pattern) { $v1 = preg_match("\x01^($pattern)\\z\x01u", $value); echo "1) $value = " . ($v1 ? "A":"N") . "\n"; $v2 = preg_match("#($pattern)#", $value); echo "2) $value = " . ($v2 ? "A":"N") . "\n"; echo $v1 != $v2 ? "!!! mismatch\n---\n" : "----\n"; } x("xaaax", '(.)\1{2,}'); x("xaaax", '(.)\2{2,}'); x("xaaax", '(?:(.)\1{2,})'); x("xaaax", '(?:(.)\2{2,})');