Stacks

Stacks is a an abstract data type and data structure based on the principle of Last In First Out. Stacks is build of by arraylists. To create a stack: Stack name = new Stack; there are several method that is important when study stacks: boolean isEmpty return true if the stack have no object in it void push( Object obj) add obj to the top of the stack; Object Pop remove the object on top from the stack; Object peekTop return the object on top, but doesn't remove it from the stack.