iOS学习之Object-C语言字符串和数值

//        1.获取字符串长度
        NSString *string1 = [NSString stringWithFormat:@"jkaruu"];
//        NSLog(@"stringLength = %ld", string1.length);
//        2.获取指定位置字符
        unichar c = [string1 characterAtIndex:0];
        NSLog(@"c = %c", c);
//        3.判断字符串的前缀 后缀
        BOOL isHasSuffix = [string1 hasSuffix:@"www."];
        NSLog(@"isHasSuffix = %d", isHasSuffix);
        BOOL isHasPerfix = [string1 hasPrefix:@"jk"];
        NSLog(@"isHasPerfix = %d", isHasPerfix);
//        4.查找某个字符串在另一个字符串的范围
        NSString *string2 = @"蓝鸥科技有限公司";
        NSString *string3 = @"蓝鸥科技";
//        NSRange 结构体，表示范围
//        location：起始位置
//        length：长度
        NSRange range = [string2 rangeOfString:string3];
        NSLog(@"location = %ld, length = %ld", range.location, range.length);
//        5.字符串截取
        NSString *string4 = @"hello world kitty";
        NSRange range1 = NSMakeRange(0, 5);
        NSString *string5 = [string4 substringWithRange:range1];
        NSLog(@"string5 = %@", string5);
        // 从指定位置向前截取，不包含指定位置的下标
        NSString *string6 = [string4 substringToIndex:7];
        NSLog(@"string6 = %@", string6);
        // 从指定位置向后截取，包含指定位置的下标
        NSString *string7 = [string4 substringFromIndex:5];
        NSLog(@"string7 = %@", string7);
//        6.字符串拼接
        NSString *string8 = @"zhangsan";
        NSString *string9 = @"lisi";
        NSString *stringL = [string8 stringByAppendingString:string9];
        NSLog(@"stringl = %@", stringL);
//        7.字符串替换
        NSString *string10 = @"wangwu";
        NSString *string11 = [string10 stringByReplacingOccurrencesOfString:string10 withString:@"liuaoran"];
        NSLog(@"string11 = %@", string11);
//        8.字符串比较
        NSInteger result = [string10 compare:string11];
        NSLog(@"result = %ld", result);
        // 判断两个字符串是否相等
        BOOL isEqual = [string10 isEqualToString:string11];
        NSLog(@"isEqual = %d", isEqual);
//        9.字符串和数值的类型转换
        NSString *s1 = @"123";
        NSInteger strValue = [s1 integerValue];
        NSLog(@"strValue = %ld", strValue);
//        10.字符串大小写之间的转换
        // 首字母大写
        string10 = [string10 capitalizedString];
        NSLog(@"string10 = %@", string10);
        // 全部字母大写
        string10 = [string10 uppercaseString];
        NSLog(@"string10 = %@", string10);
        // 全部字母小写
        string10 = [string10 lowercaseString];
        NSLog(@"string10 = %@", string10);

//        1.拼接字符串
        NSMutableString *mString1 = [NSMutableString stringWithFormat:@"zhangsan"];
        [mString1 appendString:@"666"];
        NSLog(@"mString1 = %@", mString1);
//        2.插入字符串
        [mString1 insertString:@"," atIndex:8];
        NSLog(@"mString1 = %@", mString1);
//        3.删除字符串
        [mString1 deleteCharactersInRange:NSMakeRange(3, 2)];
        NSLog(@"mString1 = %@", mString1);
//        4.字符串替换
        [mString1 replaceCharactersInRange:NSMakeRange(3, 3) withString:@"ng"];
        NSLog(@"mString1 = %@", mString1);
//        5.重置字符串
        [mString1 setString:@"zhangsan"];
        NSLog(@"mString1 = %@", mString1);

 // 创建对象
        NSRange range0 = NSMakeRange(0, 3);
        NSValue *value1 = [NSValue valueWithRange:range0];
        NSLog(@"value1 = %@", value1);
        
        // 把指针转为数值对象
        int b = 10;
        int *p = &b;
        NSValue *value2 = [NSValue valueWithPointer:p];
        NSLog(@"value2 = %@", value2);
        
        // 把数值对象转为结构体
        NSRange range3 = [value1 rangeValue];
        NSLog(@"location = %ld, length = %ld", range3.location, range3.length);
        
        // 把数值对象转为指针
        int *q = [value2 pointerValue];
        NSLog(@"q = %d", *q);