Question

Say I have NSMutableArray *array1 with 10 objects. I want to create an *array2 and add 5 objects from array1 to array2, and I want it so that when I change these object properties from array2, they also change the 5 specific objects from array1 as well. How would I do this?

Edit: Ok I think I asked the wrong question. It’s more about passing by reference and pointers, which I confuse too much:

NSMutableArray *mainArray;
NSMutableArray *secondaryArray;
NSMutableDictionary *dic1;

[mainArray addObject:dic1];
[self changeValues:[mainArray lastObject]];

-(void)changeValues:(NSMutableDictionary*)someDic
{
    [secondaryArray addObject:someDic];
    NSMutableDictionary *aDic=[secondaryArray lastObject];
    ...//some code to change values of aDic
    //by changing aDic, I want to also change the same dic from mainArray

    //so [mainArray lastObject] should be the same exact thing as [secondaryArray lastObject]
}

How would I change the above code so the changes reflect in both arrays?

Answer 1

NSMutableArray *array2 = [NSMutableArray array];
for (int i=0; i<5; ++i){
    [array2 addObject: [array1 objectAtIndex:i] ]
}

In this example you have the set of objects pointed by items of array1 as well as by items
of array2, since NSMutableArray contains pointers to objects, not objects theirselves.
Therefore, changing the object thru pointer in one array you may observe that change thru
pointer from other array.

---

Edit

@mohabitar, you already receive an answers. dic1, someDic and aDic – all these values are same. Just change aDic(or someDic) and see result.