Online PHP editor | refs for 4eGBV

<?php $tests = ['âa', 'Bbbbb', 'Éé', 'iou', 'Δδ']; foreach ($tests as $test) { echo "\n{$test}:"; echo "\n\tPREG: " , preg_match('~^\p{Lu}~u', $test) ? 'upper' : 'lower'; echo "\n\tCTYPE: " , ctype_upper(mb_substr($test, 0, 1)) ? 'upper' : 'lower'; echo "\n\t< a: " , mb_substr($test, 0, 1) < 'a' ? 'upper' : 'lower'; $chr = mb_substr ($test, 0, 1, "UTF-8"); echo "\n\tMB: " , mb_strtoupper($chr, "UTF-8") == $chr ? 'upper' : 'lower'; }