1 /*=============================NSDictionary(不可变字典)的使用=========================*/
2
3 //————————————————————————————————字典的创建————————————————————————————————
4
5 // 前面的是值(value)，后面的是键(key)，一一对应
6 // 方式一：
7 NSDictionary *dic = [[NSDictionary alloc] initWithObjectsAndKeys:@"value",@"key",@"value1",@"key1", nil];
8 NSLog(@"dic :%@",dic);
9
10 // 方式二：
11 NSDictionary *dic1 = [NSDictionary dictionaryWithObjectsAndKeys:@"value",@"key",@"value1",@"key1", nil];
12
13 // 字典的value可以说任何对象类型
14 NSArray *array = @[@"11",@"22",@"33"];
15 NSDictionary *dic2 = [[NSDictionary alloc] initWithObjectsAndKeys:array,@"key" ,nil];
16 NSLog(@"dic2 :%@",dic2);
17
18 NSDictionary *dic3 = [[NSDictionary alloc] initWithObjectsAndKeys:dic2,@"dicKey", nil];
19 NSLog(@"dic3 :%@",dic3);
20
21 // 方式三：跟方式一区分,只能是不可变字典
22 NSDictionary *dic4 = @{@"key":@"vlaue",@"key1":@"value1"};
23 NSLog(@"dic4 :%@",dic4);
24
25
26 //————————————————————————————————字典的常用方法—————————————————————————————
27
28 // count 字典元素的个数，键值一起为一个元素
29 NSUInteger len = [dic4 count];
30 NSLog(@"len = %ld",len);
31
32 //objectForKey :根据key取对应的值，如果可以没有不会报错，返回的是null
33 id obj = [dic3 objectForKey:@"dicKey"];
34 NSLog(@"obj:%@",obj);
35
36 //allKeys 获取字典的所有key,返回的是数组
37 NSArray *allKeys = [dic4 allKeys];
38 NSLog(@"allKeys :%@",allKeys);
39
40 //allValues 获取字典的所有Value,返回的是数组
41 NSArray *allValues = [dic4 allValues];
42 NSLog(@"allValues: %@",allValues);
43
44 //allKeysForObject 获取相同value的所有key
45 NSDictionary *dic5 = @{@"key":@"value",@"key1":@"value"};
46 NSArray *allKey = [dic5 allKeysForObject:@"value"];
47 NSLog(@"allKey :%@",allKey);
48
49
50 /*=============================NSMutableDictionary(可变字典)的使用=========================*/
51
52 //————————————————————————————————可变字典的创建————————————————————————————————
53
54 // 两种方式：
55 NSMutableDictionary *mDic = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"abc",@"key",@"hhhh",@"key1", nil];
56
57 NSMutableDictionary *mDic1 = [NSMutableDictionary dictionaryWithObjectsAndKeys:@"value",@"key",@"value1",@"key1", nil];
58
59 //NSMutableDictionary *mDic2 = @{@"key":@"value",@"key1":@"value1"}; 错误:不能这样创建可变字典
60 NSLog(@"mDic1:%@",mDic1);
61
62
63 //————————————————————————————————可变字典的常用方法—————————————————————————————
64
65 //setObject:forKey 给字典添加元素，修改元素
66 [mDic1 setObject:@"value2" forKey:@"key2"];
67 NSLog(@"mDic1:%@",mDic1);
68 // 修改key 对应的元素
69 [mDic1 setObject:@"kkkkk" forKey:@"key2"];
70
71 //removeObjectForKey 移除指定键的元素
72 [mDic1 removeObjectForKey:@"key"];
73 NSLog(@"mDic1:%@",mDic1);
74
75 // removeAllObjects 移除字典所有的元素
76 [mDic1 removeAllObjects];
77 NSLog(@"mDic1:%@",mDic1);
78
79 // removeObjectsForKeys 移除一组键对应的元素
80 NSArray *keys = [mDic1 allKeys];
81 [mDic1 removeObjectsForKeys:keys];
82 NSLog(@"mDic1:%@",mDic1);
83
84 //setDictionary 将新字典替换旧字典
85 [mDic1 setDictionary:mDic];
86 NSLog(@"mDic1 :%@",mDic);
87
88
89 /*===========================================字典的遍历===================================*/
90
91 NSMutableDictionary *mDic3 = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"abc",@"key",@"etrtr",@"key1", nil];
92
93 // 1、普通遍历
94 NSArray *allkey = [mDic3 allKeys];
95 for (int i = 0; i < mDic3.count; i++) {
96
97 NSString *key = [allkey objectAtIndex:i];
98 NSString *value = [mDic3 objectForKey:key];
99 NSLog(@"---%@",value);
100 }
101
102 // 2、快速遍历 obj 是字典的key
103 for (id obj in mDic3) {
104
105 NSString *value = [mDic3 objectForKey:obj];
106 NSLog(@"==%@",value);
107 }
108
109 // 3、block 遍历
110 [mDic3 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
111
112 NSLog(@">>%@",key);
113 NSLog(@">>%@",obj);
114 }];
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