IOS开发－ObjC－NSDictionary

 1 //－－－－－－－－－－－－－－－－－－不可变字典－－－－－－－－－－－－－－－－－－
 2     
 3 //    创建字典对象、并打印输出
 4     NSDictionary *dic = [NSDictionary dictionaryWithObject:@"onevalue" forKey:@"firstkey"];
 5     NSLog(@"%@",dic);
 6     
 7 //    创建字典对象，并打印输出
 8     NSDictionary *dicc = [NSDictionary dictionaryWithObjectsAndKeys:@"onevalue",  @"firstkey", @"twovalue", @"secondkey",@"threevalue", @"thirdkey",  @"threevalue", @"forthkey",nil];
 9     NSLog(@"%@",dicc);
10     
11 //    输出某个键对应的值对象
12     NSLog(@"%@",[dicc objectForKey:@"firstkey"]);
13     
14 //    计算字典的元素个数（一个键值对为一个元素）、输出某个键对应的值
15     NSLog(@"%lu,%@",[dicc count], [dicc objectForKey:@"secondkey"]);
16     
17     
18 //    使用数组存放有相同值的key
19     NSArray * arrayLastOut = [dicc allKeysForObject:@"threevalue"];
20     NSLog(@"%@",arrayLastOut);

 1 //－－－－－－－－－－－－－－－－－－可变字典－－－－－－－－－－－－－－－－－－
 2 //    创建一个空的可变字典
 3     NSMutableDictionary *mDic = [[NSMutableDictionary alloc]initWithCapacity:10];
 4     
 5 //    创建一个可变字典并赋初值
 6     NSMutableDictionary * mDicc = [NSMutableDictionary dictionaryWithObjectsAndKeys: @"onevalue", @"firstkey", @"twovalue", @"secondkey", @"threevalue", @"thirdkey", @"threevalue", @"forthkey", nil];
 7     
 8 //    把一个字典的全部值赋值给另一个字典
 9     [mDic addEntriesFromDictionary:mDicc];
10     
11     NSLog(@"%@", mDic);
12     
13 //    使用set更新字典中某个key对应的值，如果key存在，则更新value值
14     [mDic setValue: @"changeonevalue" forKey: @"firstkey"];
15     NSLog(@"%@", mDic);
16     
17 //    如果key值不存在，则增加一对key－value键值对
18     [mDic setValue:@"newvalue" forKey:@"fifthkey"];
19     NSLog(@"%@", mDic);
20     
21 //    完全替换成后面的字典内容
22     [mDicc setDictionary:dic];
23     NSLog(@"%@", mDicc);
24     
25     
26 //    删除字典中的内容－－删除1个
27     [mDicc removeObjectForKey:@"firstkey"];
28     
29 //    删除多个
30     [mDicc removeObjectsForKeys:@[@"firstkey",@"secondkey"]];
31     
32 //    删除全部内容
33     [mDicc removeAllObjects];
34     NSLog(@"%@", mDicc);

 1 //    字典遍历
 2 //    字典遍历方法1
 3     for (int x=0; x<mDicc.count; x++) {
 4         NSLog(@"%@",[mDicc objectForKey:[[mDicc allKeys] objectAtIndex:x]]);
 5     }
 6     
 7 //    字典遍历方法2
 8     for (int x=0; x<mDicc.count; x++) {
 9         NSLog(@"%@",[[mDicc allValues] objectAtIndex:x]);
10     }
11     
12 //    字典遍历方法3
13     for (id key in mDicc) {
14         NSLog(@"%@",[mDicc objectForKey:key]);
15     }
16     
17 //    字典遍历方法4
18     id dicx;
19     NSEnumerator *dicEnu = [mDicc keyEnumerator];
20     while (dicx=[dicEnu nextObject]) {
21         NSLog(@"%@",[mDicc objectForKey:dicx]);
22     }
23     
24 //    字典遍历方法5
25     id dicenu;
26     NSEnumerator * dicEnum = [mDicc objectEnumerator];
27     while (dicenu=[dicEnum nextObject]) {
28         NSLog(@"ddd%@",dicenu);
29     }