如何检测字符是大写还是小写？

Question

假设我从NSString中提取单个字符,如下所示:

[@"This is my String" characterAtIndex:0]

如何确定我得到的字符是小写还是大写字符？

感谢您的任何帮助!

Answer 1

BOOL isUppercase = [[NSCharacterSet uppercaseLetterCharacterSet] characterIsMember:[s characterAtIndex:0]];

Answer 2

unichar ch = [@"This is my String" characterAtIndex:0];

if (ch >= 'A' && ch <= 'Z') {
    // upper case
} else if (ch >= 'a' && ch <= 'z') {
   // lower case
}

请注意,这仅适用于英文字母.