______________________________不可變字典________________________________________
數組：盛放對象的有序容器 index - 對象
例如： 0 -> @"one"
2 -> @"two"
......

字典：盛放對象的無需容器，鍵值對 鍵 - 值 ==>標示(字符串) - 對象

  例如：  key         object
            @"鍵"        對象
            @"小明"      @"60分"
              ......

//1.創建
 //1.實例方法
NSDictionary *dic = [[NSDictionary alloc]init];

//2.類方法
NSIC提哦那容易*dic1 = [[NSDictionary]dictionary];

//3.通過鍵值對創建
//NSArray *array = [NSArray arrayWithObjects:@"1",@"2",nil];

NSObject *objc1 = [[NSObject alloc]init];
NSObject *objc2 = [[NSObject alloc]init];
NSObject *objc3 = [[NSObject alloc]init];

/*
  @"叁" -> objc3
  @"第一個" -> objc1
  @"tow" -> objc2
*/

NSDictionary *dic2 = [[NSDictionary alloc]initWithObjectsAndKeys:objc1,@"第一個",objc2,@"tow",objc3,@"叁",nil];

//NSDictionary *dic2_ = [NSDictionary dictionaryWithObjectsAndKeys:(nonnull id),...,nil]

/*
  1.字典打印在控制臺上，是以{}的形式輸出，多個鍵值對間使用';'相隔
  2.形式是 鍵 = 值；
  2.文字以Unicode編碼顯示  （可以在線轉換）
*/

NSLog(@"%@",dic2);

//4.快速創建 鍵:值，
NSDictionary *dic3 = @{@"a":objc1,@"b":bojc2,@"c":objc3};

NSLog(@"%@",dic3);

//5.通過字典創建 -> 相當于賦值
NSDictionary *dic4 = [[NSDictionary alloc]initWithDictionry:dic3];

//NSDictionary *dic4_ = [NSDictionary dictionaryWithDictionary:dic3];


//2.屬性
NSLog(@"count = %ld",[dic4 count]);
NSLog(@"count = %ld",dic4.count);


//2.屬性
//NSLog(@"count = %ld",[dic4 count]);
NSLog(@"count = %ld",dic4.count);

3.方法
//1.獲取字典中的對象
NSObject *objcB = [dic4 objectForKey:@"b"];
NSLog(@"%@",objcB);


//2.獲取所有的key??常用
NSArray *allkeys = [dic4 allKeys];
NSLo(@"%@",allkeys);

//3.獲取所有value
NSArray *allvalues = [dic4 allvalues];
NSLog(@"%@",allvalues);



//4.遍歷：展示容器內的所有數據

NSArray *keys = [dic4 allKeys];
for(int i = 0;i < dic4.count;i++)
{
  NSString *key = [keys objectAtIndex:i];
/*_____________________________________________*/
NSLog(@"%@",[dic4 objectForKey:key]);
}

for(NSString *key in keys)
{
    NSLog(@"%@",[dic4 objectForKey:])
}