java.util

Class Stack<E>

java.lang.Object

java.util.Vector<E>

java.util.Stack<E>

Type Parameters:

E - Entry type

All Implemented Interfaces:

Cloneable

public class Stack<E>
extends Vector<E>

The Stack class represents a last-in-first-out (LIFO) stack of objects. It extends class Vector with five operations that allow a vector to be treated as a stack. The usual push and pop operations are provided, as well as a method to peek at the top item on the stack, a method to test for whether the stack is empty, and a method to search the stack for an item and discover how far it is from the top.

Field Summary

Fields inherited from class java.util.Vector

capacityIncrement, elementCount, elementData

Constructor Summary

Constructors

Constructor and Description
Stack() Creates an empty Stack.

Method Summary

Modifier and Type	Method and Description
boolean	empty() Tests if this stack is empty.
E	peek() Looks at the object at the top of this stack without removing it from the stack.
E	pop() Removes the object at the top of this stack and returns that object as the value of this function.
E	push(E item) Pushes an item onto the top of this stack.
int	search(Object obj)

Methods inherited from class java.util.Vector

addElement, capacity, clone, contains, copyInto, elementAt, elements, ensureCapacity, firstElement, indexOf, indexOf, insertElementAt, isEmpty, lastElement, lastIndexOf, lastIndexOf, removeAllElements, removeElement, removeElementAt, setElementAt, setSize, size, toString, trimToSize

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Stack

public Stack()

Creates an empty Stack.

Method Detail

empty

public boolean empty()

Tests if this stack is empty.

Returns:

true if and only if this stack contains no items; false otherwise.

peek

public E peek()
       throws EmptyStackException

Looks at the object at the top of this stack without removing it from the stack.

Returns:

the object at the top of this stack (the last item of the Vector object).

Throws:

EmptyStackException - if this stack is empty.

pop

public E pop()
      throws EmptyStackException

Removes the object at the top of this stack and returns that object as the value of this function.

Returns:

The object at the top of this stack (the last item of the Vector object).

Throws:

EmptyStackException - if this stack is empty.

push

public E push(E item)

Pushes an item onto the top of this stack.

Parameters:

item - the item to be pushed onto this stack.

Returns:

the item argument.

search

public int search(Object obj)

Parameters:

obj - ?

Returns:

?