IOS 判断是否在限制范围内（个人）

NSCharacterSet *cs;
        cs = [[NSCharacterSet characterSetWithCharactersInString:@"1234567890"] invertedSet];
        NSString *filtered =
        [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
        BOOL basic = [string isEqualToString:filtered];
        
        return basic;