Stack class represents a last-in-first-out
(LIFO) stack of objects. It extends class Vector with five
operations that allow a vector to be treated as a stack. The usual
push and pop operations are provided, as well as a
method to peek at the top item on the stack, a method to test
for whether the stack is empty, and a method to search
the stack for an item and discover how far it is from the top.
When a stack is first created, it contains no items.
A more complete and consistent set of LIFO stack operations is
provided by the
Deque interface and its implementations, which
should be used in preference to this class. For example:
Deque<Integer> stack = new ArrayDeque<Integer>();