Can I add to a generic collection of type A values of type B ,which extends A, without any special syntax?

Question

public class Stack {
    public Stack () {....}
    public void push (E e) {....}
    public E pop () {....}
    public boolean isEmpty(){....}
}

public void p         


        

Answer 1

This problem is due the fact that collections in java are not covariant. There are numerous question on SO about it, such as this one.