Programming Visual Basic 2005

Stacks

A stack is a last-in, first-out (LIFO) collection, like a stack of dishes at a buffet table, or a stack of coins on your desk. The last dish added to the top of the stack is the first dish you take off the stack.

The principal methods for adding to and removing from a stack are Push and Pop; Stack also offers a Peek method, very much like Queue. The significant methods and properties for Stack are shown in Table 17-4.

Table 17-4. Stack methods and properties

Method or property	Purpose
Count	Public property that gets the number of elements in the Stack
Clear	Removes all objects from the Stack
Clone	Creates a shallow copy
Contains	Determines if an element is in the Stack
CopyTo	Copies the Stack elements to an existing one-dimensional array
GetEnumerator	Returns an enumerator for the Stack
Peek	Returns the object at the top of the Stack without removing it
Pop	Removes and returns the object at the top of the Stack
Push	Inserts an object at the top of the Stack
ToArray	Copies the elements to a new array