Question

I’m new ios developer, I want to compare and change attributes

Array1 = (object1,object2, object3, object4)
Array2 = (object2,object4, object5, object8)

Compare Array1 and Array2
If same objects are in Array2, change attributes in the objects.

In this case above, Object2 and Object4 should be changed..

How should I do??

Please help me!!

Answer 1

You can use sets for this

NSMutableSet *array1Set = [NSMutableSet setWithArray:array1];
NSSet *array2Set = [NSSet setWithArray:array2];
[array1Set intersectSet:array2Set];

You now have a set with just the objects which are in both arrays.
Now you can use enumerateObjectsUsingBlock: on the set to manipulate the objects or convert the set back to an array NSArray *filteredArray = [array1Set allObjects]