1 #import <Foundation/Foundation.h>
 2 
 3 int main(int argc, const char * argv[])
 4 {
 5     @autoreleasepool
 6     {
 7         /*
 8          字典：
 9          存储的内存不是连续的
10          用key和value进行对应（键值）
11          kvc 键值编码
12          */
13         NSDictionary *dict1 = [NSDictionary dictionaryWithObject:@"1" forKey:@"a"];
14         NSLog(@"dict1 = %@", dict1);
15         
16         NSDictionary *dict2 = [NSDictionary dictionaryWithObjects:[NSArray arrayWithObjects:@"1", @"2", @"3", nil] forKeys:[NSArray arrayWithObjects:@"a", @"b", @"c", nil]];
17         NSLog(@"dict2 = %@", dict2);
18         
19         NSDictionary *dict3 = @{@"1":@"a", @"2":@"b"};//1, 2 代表key，a, b 代表value
20         NSLog(@"dict3 = %@", dict3);
21         int count = (int)[dict2 count];
22         NSLog(@"count = %d", count);
23         
24         NSString *value1 = [dict2 valueForKey:@"b"];
25         NSLog(@"value1 = %@", value1);
26         
27         NSString *value2 = [dict2 objectForKey:@"b"];
28         NSLog(@"value2 = %@", value2);
29         
30         NSArray *allValues = [dict2 allValues];
31         NSLog(@"allValues = %@", allValues);
32         NSArray *allKey = [dict2 allKeys];
33         NSLog(@"allKey = %@", allKey);
34         
35         NSArray *array = [dict2 objectsForKeys:[NSArray arrayWithObjects:@"a", @"b", @"d", nil] notFoundMarker:@"not fount"];
36         NSLog(@"array = %@", array);
37         
38         //遍历字典
39         for(NSString *key in dict2)
40         {
41             NSLog(@"%@ = %@", key, [dict2 objectForKey:key]);
42         }
43         for(id object in dict2)
44         {
45             NSLog(@"%@ = %@", object, [dict2 objectForKey:object]);
46         }
47         //用枚举器遍历
48         NSEnumerator *en = [dict2 keyEnumerator];
49         id key = nil;
50         while (key = [en nextObject])
51         {
52             NSLog(@"key - %@", key);
53         }
54 #pragma mark - NSMutableDictionary
55         NSMutableDictionary *dictM = [[NSMutableDictionary alloc] init];
56         //添加键值对
57         [dictM setValue:@"1" forKey:@"a"];
58         [dictM setValue:@"2" forKey:@"b"];
59         NSLog(@"dictM = %@", dictM);
60         //删除键值对
61 //        [dictM removeAllObjects];
62 //        [dictM removeObjectForKey:@"b"];
63         [dictM removeObjectsForKeys:[NSArray arrayWithObjects:@"a", @"b", nil]];
64         NSLog(@"dictM = %@", dictM);
65         
66     }
67     return 0;
68 }