5.3 Stacks

The Stack class is a subclass of Vector that implements a last-in-first-out (LIFO) object stack. The Stack class uses the following methods to provide stack behavior:

• The push() method pushes an object onto the top of the stack.

• The pop() method removes and returns the top element from the stack. If the stack is empty, pop() throws an EmptyStackException.

• The peek() method returns, but does not remove, the top element from the stack. If the stack is empty, peek() throws an EmptyStackException.

• The empty() method returns true if and only if the stack is empty.