iOS NSDictionary 按照key排序 nsdictionary setvalue

<span style="font-size:18px;">/*字典存在的价值 :
         0. 字典类是用于保存具有映射关系(key - value对)的数据, 字典一旦创建,键值对就不可更改, 不可添加, 不可删除.仅能读取key 或者 value
         1. 大容器,用来存储多个数据, 
         2.用来存储的数据具有--对应的关系.(使用key 来标识 value).
         3.对于字典中的一对键值对(key - value)叫做字典中的一个元素. 也叫一个条目, 只要是对象就可以, 不限制类型.
         4.字典是无序的
         5.字典中的key是唯一的, 一个key 只能对应一个value ,一个value 可以对应多个 key.*/
        //1.创建字典对象
        //(1)便利构造器
        NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:@"Summer", @"name", @"male", @"gender", @20, @"height", @12, @"age", nil];
        NSLog(@"%@", dic);
        //(2)初始化方法
        NSDictionary *dic1 = [[NSDictionary alloc] initWithObjectsAndKeys:@"Summer", @"name", @"male", @"gender", @20, @"height", @12, @"age", nil];
        NSLog(@"%@", dic1);
        //2.求字典元素个数
        NSInteger count = [dic count];
        NSLog(@"count = %ld", count);
        //3.获取所有的key
        NSArray *keys = [dic allKeys];
        NSLog(@"%@", keys);
        //4获取所有的value
        NSArray *value = [dic allValues];
        NSLog(@"%@", value);
        //5.根据key获取对应的value
        //通过为对象字典发送objeForKey消息可以根据给定的key去获取对应的value,这里如果给定的key不存在,则返回null作为value,表示没有找到对应的value.
        NSString *name = [dic objectForKey:@"name"];
        NSLog(@"name = %@", name);
        NSNumber *age = [dic objectForKey:@"age1"];
        NSLog(@"age = %@", age);
        NSString *gender = [dic objectForKey:@"gender"];
        NSLog(@"gender = %@", gender);
        NSNumber *height = [dic objectForKey:@"height"];
        NSLog(@"height = %@", height);

        //字典快速遍历
        //快速遍历: 对于数组来说,遍历得到的是数组中的每一个元素
        //对于字典来说, 遍历得到的是字典中的key, 然后通过key 获取 value
        for (NSString *key in dic) {
            //检索到key之后,通过objectForKey 获取key对于的value
            NSLog(@"%@", [dic objectForKey:key]);
        }
        
        
        
        
        //对于可变字典来说,比不可变字典多了增加, 删除, 修改操作
        //1.创建对象
        NSMutableDictionary *mutableDic = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"Summer", @"name1", @"Sunshine", @"name2", @"Angle", @"name3", nil];
        NSLog(@"%@", mutableDic);
        //2.求字典元素个数
        NSInteger count = [mutableDic count];
        NSLog(@"count = %ld", count);
        //3.删除元素
        [mutableDic removeObjectForKey:@"name3"];
        NSLog(@"%@", mutableDic);
        [mutableDic removeAllObjects];
        NSLog(@"%@", mutableDic);
        //批量删除
        [mutableDic removeObjectsForKeys:[NSArray arrayWithObjects:@"name1", @"name2", nil]];
        NSLog(@"%@", mutableDic);
        //4.添加元素
        [mutableDic setObject:@"Kimi" forKey:@"name1"];
        NSLog(@"%@", mutableDic);
        //5.修改key对应的value
        [mutableDic setObject:@"Angle" forKey:@"name1"];
        NSLog(@"%@", mutableDic);
        //setObject: forKey: 工作原理
//        先根据指定得key查找字典中是否存在相同的key.(查找字典中是否存在指定的key).如果存在则修改key对应的value. 如果不存在,在字典中添加一个元素,key - value 键值对</span>

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<pre name="code" class="objc"><span style="font-size:18px;">//集合
//1.集合与数学集合一样, 存储的元素互不相同(互异性)(唯一性).
//2.存储的元素无序性
//3.存储元素必须是对象类型
        //1.创建集合对象
        //(1)遍历构造器方法
        NSSet *set1 = [NSSet setWithObjects:@"Summer", @"Sunshine", @"Angle", @"procedure", @"oriented", @"programming", nil];
        NSLog(@"%@", set1);
        //(2)初始化方法
        NSSet *set2 = [[NSSet alloc] initWithObjects:@"Summer", @"Sunshine", @"Angle", @"procedure", @"oriented", @"programming", @"Object", @"oriented", @"programming", nil];
         NSLog(@"%@", set2);
        //2.获取元素个数
        NSInteger count = [set2 count];
        NSLog(@"count = %ld", count);
        //3.获取集合中的某个元素(为了方便性)
        NSString *str1 = [set2 anyObject];
        NSLog(@"%@", str1);
        NSString *str2 = [set2 anyObject];
        NSLog(@"%@", str2);
        NSString *str3 = [set2 anyObject];
        NSLog(@"%@", str3);
        NSString *str4 = [set2 anyObject];
        NSLog(@"%@", str4);
        NSString *str5 = [set2 anyObject];
        NSLog(@"%@", str5);
        //4.判断集合中是否包含某个对象
        BOOL isExist = [set2 containsObject:@"Summer"];
        NSLog(@"%d", isExist);
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<span style="font-size:18px;">//可变集合
         NSMutableSet *set2 = [[NSMutableSet alloc] initWithObjects:@"Summer", @"Sunshine", @"Angle", @"procedure", @"oriented", @"programming", @"Object", @1, @"programming", @"programming", @"programming", @1, @1,nil];
        NSLog(@"%@", set2);
        //1.添加元素
        [set2 addObject:@"Cindy"];
         NSLog(@"%@", set2);
        //2.移除元素
        [set2 removeObject:@"Summer"];
         NSLog(@"%@", set2);
        
        //求带有记录对象重复次数的子类NSCountSet
        NSCountedSet *countedSet = [NSCountedSet setWithObjects:@"programming", @"programming",@"programming",nil];
        //通过实例方法countForObject：来得到指定对象的重复次数
        NSInteger count = [countedSet countForObject:@"programming"];
        NSLog(@"count = %ld", count);
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