测试php中给定字符的大写或小写类型的最佳方法是什么？

Question

不管当前本地语言的事实如何，一种检测字符是大写还是小写的理想方式是什么。还有更直接的功能吗？假设：将内部字符编码设置为UTF-8，并且本地浏览器会话为en-US，en; q = 0.5，并且已安装Multibyte String扩展名。不要使用ctype_lower或ctype_upper。请参阅下面的测试代码，该代码应该是多字节兼容的。$encodingtype = 'utf8';$charactervalue = mb_ord($character, $encodingtype);$characterlowercase = mb_strtolower($character, $encodingtype) ;$characterlowercasevalue = mb_ord(mb_strtolower($character, $encodingtype));$characteruppercase = mb_strtoupper($character, $encodingtype);$characteruppercasevalue = mb_ord(mb_strtoupper($character, $encodingtype));// Diag Infoecho 'Input: ' . $character . "<br />";echo 'Input Value: ' . $charactervalue = mb_ord($character, $encodingtype) . "<br />" . "<br />";echo 'Lowercase: ' . $characterlowercase = mb_strtolower($character, $encodingtype) . "<br />";echo 'Lowercase Value: ' . $characterlowercasevalue = mb_ord(mb_strtolower($character, $encodingtype)) . "<br />" . "<br />";echo 'Uppercase: ' . $characteruppercase = mb_strtoupper($character, $encodingtype) . "<br />";echo 'Uppercase Value: ' . $characteruppercasevalue = mb_ord(mb_strtoupper($character, $encodingtype)) . "<br />" . "<br />";// Diag Infoif ($charactervalue == $characterlowercasevalue and $charactervalue != $characteruppercasevalue){    $uppercase = 0;    $lowercase = 1;    echo 'Is character is lowercase' . "<br />" . "<br />";}elseif ($charactervalue == $characteruppercasevalue and $charactervalue != $characterlowercasevalue ){    $uppercase = 1;    $lowercase = 0;    echo 'Character is uppercase' . "<br />" . "<br />";}else{    $uppercase = 0;    $lowercase = 0;    echo 'Character is neither lowercase or uppercase' . "<br />" . "<br />";}//测试1 A // //输出->字符为大写//测试2 z // //输出->字符为小写//测试3 + // Output->字符为小写//测试4 0 // Output->字符既不大写也不大写//测试5ǻ//带有小号和小号的拉丁小写字母A //输出->字符为小写//测试6Ͱ希腊大写字母HETA // //输出->字符为大写//测试7''NULL // Output->字符既不小写也不大写