OC学习笔记 Foundation 集合类 字典Dictionary

 1  NSDictionary *dic = [NSDictionary dictionaryWithObject:@"dajie" forKey:@"name"];//直接创建字典
 2     id object = [dic objectForKey:@"name"];// 取出name键对应值
 3     NSLog(@"%@",object);

1       NSArray *obj = @[@"dajie",@"ly"];
2       NSArray *keys = @[@"name",@"address"];
3       NSDictionary *dic1 = [NSDictionary dictionaryWithObjects:obj forKeys:keys];//创建字典
4       NSLog(@"%@",dic1);

1      NSDictionary *dic2 = [NSDictionary dictionaryWithObjectsAndKeys:@"dajie",@"name",@"ly",@"address", nil];//nil不可少
2      NSLog(@"\n---%@",dic2);

3      id obj2 = [dic2 objectForKey:@"name"];//根据键取出对应的值
4      NSLog(@"%@",obj2);

　　　　//xcode 新特性 开发中常用
15     NSDictionary *dic3 = @{@"name" : @"dajie",@"address":@"ly",@"qq":@"12324124"};
16     NSLog(@"%@\n--%@--%ld",dic3,[dic3 objectForKey:@"name"],dic3.count);

2      NSMutableDictionary *mdic = [NSMutableDictionary dictionary];//创建

//添加键值对
20     [mdic setObject:@"dajie" forKey:@"person"];
21     [mdic setObject:@"hashiqi" forKey:@"dog"];
22     [mdic setObject:@"shapi" forKey:@"dog"];  //主键一样字典元素前者会被后者覆盖
23     NSString *str = mdic[@"dog"];
24     NSLog(@"%@",str);
25   //删除
26     [mdic removeAllObjects];
27     [mdic removeObjectForKey:@"dog"];
28     NSLog(@"%@",mdic);

30  　　NSDictionary *newDic = @{
31                              @"name": @"dajie",
32                              @"dog":@"HASHIQI"
　　　　};
33     NSArray *key = [newDic allKeys];//取出所有的key
34     for (int i;  i < newDic.count; i++) {
35         NSString *keys = key[i];
36         NSString *value = newDic[keys];
37         NSLog(@"%@ = %@",keys,value);
38     }

//推荐使用 快速遍历
40     [newDic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
41         NSLog(@"%@ - %@ ",key ,obj );
42     }];