OC 第七天 字典 lesson7

NSDictionary 常用方法

NSDictionary用于保存具有映射关系的数据，因此，NSDictionary集合里保存着两组值：

一组用于保存NSDictionary里的key

另一组用于保存NSDictionary里的value

其中key与value都可以是任何引用类型的数据，key与value之间存在单向一对一的关系。（key不允许重复）

1.创建字典对象；

        NSDictionary * dicYaoGe = [NSDictionary dictionaryWithObjectsAndKeys:@"瑶哥", @"name",
                                   @"?", @"sex",
                                   @"18", @"age",
                                   @"105", @"weight",
                                   nil];
        NSLog(@"%@",dicYaoGe);

注意：此处写法比较反人类，value在前，key在后。

运行结果：

2014-09-19 20:47:06.329 oc07_字典[6837:303] {

age = 18;

name = "\U7476\U54e5";

sex = "?";

weight = 105;

}

2.获取所有key值

        NSLog(@"%@", [dicYaoGe allKeys]);

运行结果：

2014-09-19 20:47:06.473 oc07_字典[6837:303] (

age,

sex,

weight,

name

)

3.获取所有value值

 NSLog(@"%@", [dicYaoGe allValues]);

运行结果：

2014-09-19 20:47:06.474 oc07_字典[6837:303] (

18,

"?",

105,

"\U7476\U54e5"

)

4.通过key值查询value

<span style="white-space:pre">	</span>NSLog(@"%@",[dicYaoGe objectForKey:@"weight"]);

运行结果：

2014-09-19 20:47:06.474 oc07_字典[6837:303] 105

快速遍历方法：

        for (NSString *key in dicYaoGe) {
            NSLog(@"%@ - %@",key ,[dicYaoGe objectForKey:key]);
        }

运行结果：

2014-09-19 20:47:06.475 oc07_字典[6837:303] age - 18

2014-09-19 20:47:06.476 oc07_字典[6837:303] sex - ?

2014-09-19 20:47:06.476 oc07_字典[6837:303] weight - 105

2014-09-19 20:47:06.477 oc07_字典[6837:303] name -
瑶哥

NSMutableDictionary
常用方法

            NSMutableDictionary *dicZijie = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                             @"王子杰",@"name",
                                             @"难以判断",@"sex",
                                             @"七老八十",@"age",
                                             @"200",@"weight",nil];
            for (NSString *key in dicZijie) {
                NSLog(@"%@-%@",key , [dicZijie objectForKey:key]);
            }

运行结果：

2014-09-19 20:57:55.310 oc07_字典[6858:303] age--七老八十

2014-09-19 20:57:55.311 oc07_字典[6858:303] hoby--男

2014-09-19 20:57:55.311 oc07_字典[6858:303] weight--200

2014-09-19 20:57:55.312 oc07_字典[6858:303] name--王子杰

1.添加键值对。

<span style="white-space:pre">	</span>[dicZijie setValue:@"LOL" forKey:@"hoby"];

2.修改key对应的value

<span style="white-space:pre">	</span>[dicZijie setValue:@"男" forKey:@"hoby"];

3.删除键值对。

<span style="white-space:pre">	</span>[dicZijie removeObjectForKey:@"sex"];

4.通过for循环遍历所有键值对

<span style="white-space:pre">	</span>for (NSString *key in dicZijie) {
                NSLog(@"%@-%@",key , [dicZijie objectForKey:key]);
            }

运行结果：

2014-09-19 21:00:49.198 oc07_字典[6872:303] age-七老八十

2014-09-19 21:00:49.199 oc07_字典[6872:303] hoby-男

2014-09-19 21:00:49.199 oc07_字典[6872:303] weight-200

2014-09-19 21:00:49.200 oc07_字典[6872:303] name-王子杰

对于一个数组中字典的遍历：

  <span style="white-space:pre">	</span>NSDictionary *dicDaGe = [NSDictionary dictionaryWithObjectsAndKeys:@"大哥", @"name",
                                 @"卖药", @"hoby",
                                 @"男", @"sex",nil];
        NSMutableArray *tongJi = [NSMutableArray arrayWithObjects:dicZijie,dicYaoGe,dicDaGe, nil];

        for (NSDictionary *dic in tongJi) {
            NSLog(@"______________");
            for (NSString *key in dic) {
                NSLog(@"%@--%@",key,[dic objectForKey:key]);
            }
        }

运行结果：

2014-09-19 21:00:49.201 oc07_字典[6872:303] ______________

2014-09-19 21:00:49.201 oc07_字典[6872:303] age--七老八十

2014-09-19 21:00:49.201 oc07_字典[6872:303] hoby--男

2014-09-19 21:00:49.202 oc07_字典[6872:303] weight--200

2014-09-19 21:00:49.202 oc07_字典[6872:303] name--王子杰

2014-09-19 21:00:49.203 oc07_字典[6872:303] ______________

2014-09-19 21:00:49.203 oc07_字典[6872:303] age--18

2014-09-19 21:00:49.204 oc07_字典[6872:303] sex--?

2014-09-19 21:00:49.204 oc07_字典[6872:303] weight--105

2014-09-19 21:00:49.205 oc07_字典[6872:303] name--瑶哥

2014-09-19 21:00:49.205 oc07_字典[6872:303] ______________

2014-09-19 21:00:49.206 oc07_字典[6872:303] name--大哥

2014-09-19 21:00:49.206 oc07_字典[6872:303] hoby--卖药

2014-09-19 21:00:49.207 oc07_字典[6872:303] sex--男