翻译

结尾的 set 和 NSSet 一点关系都没有

+ (NSCharacterSet *)controlCharacterSet;                  ascii 码表中的控制字符  

+ (NSCharacterSet *)whitespaceCharacterSet;  两端的空格

+ (NSCharacterSet *)whitespaceAndNewlineCharacterSet;  两端的空格和两端的新一行符”\r”

+ (NSCharacterSet *)decimalDigitCharacterSet;  两端的小数点以外的字符

+ (NSCharacterSet *)letterCharacterSet;  两端的字母

+ (NSCharacterSet *)lowercaseLetterCharacterSet;  两端的小写

+ (NSCharacterSet *)uppercaseLetterCharacterSet;   两端的大写

+ (NSCharacterSet *)nonBaseCharacterSet; ？？？？？

+ (NSCharacterSet *)alphanumericCharacterSet; 两端的中文，英文，数字

+ (NSCharacterSet *)decomposableCharacterSet; 可分解的？？？？

+ (NSCharacterSet *)illegalCharacterSet; 非法的？？？

+ (NSCharacterSet *)punctuationCharacterSet; 标点符号

+ (NSCharacterSet *)capitalizedLetterCharacterSet; 印刷体？？？？

+ (NSCharacterSet *)symbolCharacterSet; 符号????

+ (NSCharacterSet *)newlineCharacterSet NS_AVAILABLE(10_5, 2_0);  "\r"

+ (NSCharacterSet *)characterSetWithRange:(NSRange)aRange;

+ (NSCharacterSet *)characterSetWithCharactersInString:(NSString *)aString;

+ (NSCharacterSet *)characterSetWithBitmapRepresentation:(NSData *)data;

+ (NSCharacterSet *)characterSetWithContentsOfFile:(NSString *)fName;