2 instances of 1 class don't share their property - swift

Question

I have 2 classes(A,B) that have instances of another class(C) as their property. Class C have property with some values(no matter what type). A class have methods that removes and append objects from/to C. B class have method that returns objects from class C. Now classes A and B have their views, on A view user able to append and remove object from C and view updates everytime when C changes, and view B call B class method when appear to load object from C, but method returns 0 objects.Here is code example:
class C{
var property = [Something]
}
class A{
var c = C()
func appendOrremove(){
//... some action
}
}
class B{
var c = C()
func getProperty()->[Something]{
//... return property of c
}
}
I can provide exact my code where I faced the problem, but it will much more code than above.Thanks in advance!
Okey I better show my code
class FavoriteBeers{
var favoriteBeers = [Beer]()
}
class BeersListInteractor:BeersListInteractorProtocol{
private var favoriteBeers = FavoriteBeers()
func addToFavorites(beer: Beer){
favoriteBeers.favoriteBeers.append(beer)
saveFavoriteBeers()
}
func removeFromFavorites(_ beer: Beer) {
favoriteBeers.favoriteBeers.removeAll { $0 == beer }
saveFavoriteBeers()
}
}
class FavoriteBeersInteractor:FavoriteBeersInteractorProtocol{
private var favoriteBeers = FavoriteBeers()
func getFavoriteBeers()-> [Beer]{
return favoriteBeers.favoriteBeers
}
}

Answer 1

You don't show how objects of the A and B classes are related but that will be important for how they share the c object. Here's a playground example that would work if something else controls A and B instances.
class Something{
}
class C{
var property = [Something()]
}
class A{
var c: C?
func appendOrremove(){
}
}
class B{
var c: C?
func getProperty()->[Something]{
return c?.property ?? []
}
}
let exC = C()
let exA = A()
exA.c = exC
let exB = B()
exB.c = exC
Another common situation would have A objects create B objects. In that case you might want classes defined something like:
class A{
var c = C()
var b: B
init() {
b = B(c)
}
func appendOrremove(){
}
}
class B{
var c: C
init(_ inC: C) {
c = inC
}
func getProperty()->[Something]{
return c.property
}
}