you cannot add/remove objects from a NSArray because it is immutable. But you can update one of the objects.
In contrast NSMutableArray can add/remove objects and has an addObjectsFromArray method which takes in an NSArray as an argument.
Are the objects now in the NSMutableArray originally in an NSArray by reference or value?
Meaning if I update a property of an object in an NSArray that was previously passed to an NSMutableArray, will the object in NSMutableArray see that change and vice versa?
NSArrayorNSMutableArraystores the references of objects.In your case Yes changes will be reflected as
NSArrayandNSMutableArrayare having the reference of same object.