MOST WEB BROWSERS HAVE A HISTORY OF THE PAGES THAT USERS HAVE VISITED.WHEN FIRST THE USER ENTERS A WEB ADDRESS,IT IS STORED IN THE PAGES VISITED.WHEN THE USER CLICKS A LINK IN THE VISITED PAGES,THAT PAGE IS ADDED ON TOP OF THE PREVIOUSLY VISITED PAGES.
THE USER CAN THEN PRESS THE BACK BUTTON TO RE-VISIT PREVIOUS PAGES;AND IF WHEN VISITING PREVIOUS PAGES,THE USER CAN PRESS THE FORWARD KEY TO VISIT MORE PAGES.
THINK OF THIS AS A STACK OF WEB-PAGES HISTORY,WHERE THE PAGE URL ARE STRING OBJECT,AND EACH PAGE AS AN ELEMENT IN A STACK.THE TASK IS TO IMPLEMENT THE PAGES HISTORY USING THE STACK DATA STRUCTURE.