Programming Language Python:

A "Stack" is an abstract data type for storing a collection of items, where items are both added and removed from one end of the collection. The methods for adding and removing items from a stack are traditionally called "push()" and "pop()" respectively. A method called "peek()" returns the value on the top of the stack, but does not remove it from the stack. A "size()" method returns the number of items on the stack, and a method "is_empty()" returns a boolean indicating if the stack is empty.

For this exercise, you will provide a complete implementation of the Stack ADT. You can implement the Stack ADT in any way that you like, but using a Python list to store the items is certainly the simplest way.

The method names are given below as a guide to help you:

class Stack: def __init__(self): def is_empty(self): def push(self, item): def pop(self): def peek(self): def size(self): 

For example:

Test	Result
s = Stack() print(s.is_empty())	True
s = Stack() s.push(1) s.push(2) s.push(3) s.push(4) while not s.is_empty(): print(s.pop())	4 3 2 1