1--TEST-- 2Case-insensitive string comparisons use case folding 3--EXTENSIONS-- 4mbstring 5--FILE-- 6<?php 7 8$tests = [ 9 ["K", "K"], 10 ["k", "K"], 11 ["Å", "Å"], 12 ["å", "Å"], 13 ["ß", "ẞ"], 14 ["Θ", "ϴ"], 15 ["θ", "ϴ"], 16 ["ϑ", "ϴ"], 17 ["Ω", "Ω"], 18 ["ω", "Ω"], 19 ["I", "ı"], 20 ["i", "ı"], 21]; 22 23foreach ($tests as list($a, $b)) { 24 var_dump(mb_stripos($a, $b)); 25} 26 27?> 28--EXPECT-- 29int(0) 30int(0) 31int(0) 32int(0) 33int(0) 34int(0) 35int(0) 36int(0) 37int(0) 38int(0) 39bool(false) 40bool(false) 41