// 使用实例方法创建NSString对象

        NSString *string1 = [[NSStringalloc]initWithFormat:@"姓名流年"];

        NSLog(@"%@", string1);

        NSString *string2 = [[NSStringalloc]initWithFormat:@"Ming"];

        NSLog(@"%@", string2);

        NSString *string3 = [[NSStringalloc]initWithFormat:@"姓名：%@  年龄：%d  爱好：%@", @"嘿嘿", 100, @"吃、喝、玩" ];

        NSLog(@"%@",string3);

        //把字符串转为数值类型

        NSInteger intstr = [@"124" integerValue];

        NSLog(@"%ld",intstr);

        double m = [@"1000.00432" doubleValue];

        NSLog(@"%lf", m);

        //大小写转换

        NSString *m1 = @"Have a good day";

        NSString *m2 = [m1 uppercaseString];

        NSString *m3 = [m1 lowercaseString];

        NSString *m4 = [m1 capitalizedString];

        NSLog(@"===%@  ++++%@  ****%@", m2, m3, m4);

        //可变字符串

        NSMutableString *string1 = [[NSMutableString alloc]initWithFormat:@"蓝欧科技有限公司"];

        NSMutableString *string2 = [NSMutableString stringWithFormat:@"蓝欧科技有限公司"];

        //拼接字符串

        [string1 appendString:@".txt"];

        NSLog(@"%@", string1);

        //插入字符串

        [string2 insertString:@"3G" atIndex:2];

        NSLog(@"%@", string1);

        //删除字符串

        [string1 deleteCharactersInRange:NSMakeRange(2, 2)];

        NSLog(@"%@", string1);

        NSString *p0 = @"aBcD_EfGk";

        if([p0 hasSuffix:@"EfGk"])

        {NSString *p1 = [p0 stringByReplacingOccurrencesOfString:@"EfGk"withString:@"WXYZ"];

        NSString *p2 = [p1 lowercaseString];

            NSLog(@"%@",p2);

    }

        //使用类方法创建NSString对象

        NSString *string2 = [NSStringstringWithFormat:@"蓝欧科技有限公司"];

        NSLog(@"%@", string2);

        //直接赋值

        NSString *string3 = @"abc";

        NSLog(@"%@", string3);

        //获取字符串长度

        NSInteger string1Length = [string1 length];

        NSLog(@"%ld", string1Length);

        NSInteger len2 = [string2 length];

        NSLog(@"%ld", len2);

        //判断字符串前缀

        BOOL result1= [string1 hasPrefix:@"m"];

        NSLog(@"------%d", result1);

        BOOL result2 = [string1 hasSuffix:@"年"];

        NSLog(@"%d",result2);

        //查找字符串位置

        NSRange range1 = [string2 rangeOfString:@"有"];

        NSLog(@"位置：%ld  长度：%ld", range1.location, range1.length);

        NSRange kk = [string2 rangeOfString:@"科技有"];

        NSLog(@"weizhi:%ld  lengt:%ld", kk.location, kk.length);

        //截取字符串

        NSString *p = [[string2 substringFromIndex:2]substringToIndex:4];

        NSString *p1 = [string2 substringToIndex:4];

        NSLog(@"~~~~~~~%@, %@", p, p1);

//NSArray数组类

        //1.使用实例方法创建数组

        NSArray *array1 = [[NSArrayalloc]initWithObjects:@"1",@"2",@"3", nil];

        NSLog(@"%@", array1);

        //2.使用类方法创建数组

        NSArray *array2 = [NSArrayarrayWithObjects:@"4",@"5",@"6", nil];

        NSLog(@"%@", array2);

        //3.获取数组元素个数

        NSUInteger count = [array1 count];

        NSLog(@"%ld", count);

        //4.根据索引值获取对象

       NSString *p = [array1 objectAtIndex:1];

        NSLog(@"%@", p);

        //5.获取对象在数组中的索引值

        NSUInteger index = [array1 indexOfObject:@"3"];

        NSLog(@"%ld", index);

        //NSMutableArray数组类

        //1.使用实例方法创建

        NSMutableArray *m1 = [[NSMutableArrayalloc]initWithObjects:@"a",@"b",@"c", nil];

        //2。使用类方法创建

        NSMutableArray *m2 = [NSMutableArrayarrayWithObjects:@"a",@"b",@"c", nil];

        //3.添加元素

        [m1 addObject:@"d"];

        NSLog(@"%@",m1);

        //4.插入元素

        [m1 insertObject:@"ZZ"atIndex:1];

        NSLog(@"%@",m1);

        //5.删除元素

        [m1 removeObject:@"ZZ"];

        NSLog(@"%@",m1);

        //6.替换元素

        [m1 replaceObjectAtIndex:2withObject:@"Ming"];

        NSLog(@"%@", m1);

        //7.交换指定位置的2个元素

        [m1 exchangeObjectAtIndex:1withObjectAtIndex:2];

        NSLog(@"%@", m1);

        //8.根据对象来交换两个元素的位置

        [m1 exchangeObjectAtIndex:[m1 indexOfObject:@"a"] withObjectAtIndex:[m1 indexOfObject:@"Ming"]];

        NSLog(@"%@",m1);

        //9.遍历数组对象 （循环输出）

        for (int i = 0; i < [m1 count]; i ++) {

            NSString *m2 = [m1 objectAtIndex:i];

            NSLog(@"普通遍历:%@",m2);

        }

        for (NSString *str  in m1) {

            NSLog(@"快速遍历:%@",str);

        }

        NSMutableArray *book = [NSMutableArrayarrayWithObjects:@"AAA",@"BBB",@"CCC",@"DDD", nil];

        [book addObject:@"MMM"];

        [book removeObject:@"CCC"];

        [book replaceObjectAtIndex:0withObject:@"WWW"];

        NSUInteger i = [book indexOfObject:@"BBB"];

        NSString *p1 = [book objectAtIndex:i];

        NSLog(@"%@", p1);

        for (NSString *list  in book) {

            NSLog(@"%@",list);

        }

        NSLog(@"%@", book);

        NSMutableArray *n = [NSMutableArrayarrayWithObjects:@"1",@"2",@"3", nil];

        NSNumber *num = [NSNumbernumberWithFloat:4.4];

        NSLog(@"%@",num);

        [n addObject:num];

        NSLog(@"%@",n);

        NSNumber *n1 = [n objectAtIndex:3];

        NSLog(@"%@",n1);

        CGFloat n2 = [n1 intValue];

        NSLog(@"%.2lf",n2);

        NSRange p2 = NSMakeRange(4, 4);

        NSString *p3 = [string2 substringWithRange:NSMakeRange(2,4)];

        NSLog(@"%@", p3);

        //拼接

        NSString *p4 = [string2 stringByAppendingString:@"123"];

        NSLog(@"%@",p4);

        //替换

        NSString *p5 = [string2 stringByReplacingOccurrencesOfString:@"蓝欧"withString:@"abcdef"];

        NSLog(@"%@", p5);

        //比较

        NSString *p6 = @"a";

        NSString *p7 = @"B";

        NSComparisonResult result3 = [p6 compare:p7];

        NSLog(@"%ld",result3);