NSMutableDictionary Adding multiple objects to one key

Question

How do I add multiple objects to same key in an NSMutableDictionary? I cannot find the right method. The setObject method only updates a single object in the key array. The method addObject: forkey: in the NSMutableDictionary isn't available and is causing a crash when it is used.

The dictionary is read from a plist file.

The Dictionary:

temp = {
    nickname : score 
        item 0 = level1;
        item 1 = level2;
        item 3 = level3;
    score 
        item 0 = 400;
        item 1 = 400;
        item 3 = 400;
}

Here is the code:

NSMutableDictionary *newDict = [[NSMutableDictionary alloc] init];
str_nickname = [temp objectForKey:@"nickname"];
for (NSString *key in str_nickname){
    if ([key isEqualToString:@"level2"]) {  //replace object with new name
        [newDict setObject:@"new level" forKey:@"nickname"];
    } else {
        [newDict addObject:key forKey:@"nickname"];   //wont work!!!
    }
}

Also I want to update the new score in the new dictionary and have to update this at the corresponding level-object, maybe by the index?

Answer 1

if you want to have multiple objects stored under the same key in a dictionary, your only chance is putting them into an

• array
• other dictionary
• set
• bag
• any collection type you fancy

and storing that in your dictionary. Reason is, dictionaries are key-value-PAIRINGS. The entire architecture isnt made to support a key that corresponds to more than one object. The objects would be indistuguishable for the system, hence, no dice.

EDIT: If you want to access the object by using an index, i guess your best bet is the Array-Version. Store a Mutable Array in your dictionary for the key "nickname", then add Objects to that array. To Store:

[myDictionary setObject:[NSMutableArray array] ForKey:@"nickname"];
[[myDictionary objectForKey:@"nickname"] addObject:yourObject];

To retrieve:

[[myDictionary objectForKey:@"nickname"] objectAtIndex:index];