java.util.Stack Maven / Gradle / Ivy
/*
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stub files, must be accompanied by this notice in its entirety.
This work corresponds to the API signatures of JSR 219: Foundation
Profile 1.1. In the event of a discrepency between this work and the
JSR 219 specification, which is available at
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*/
package java.util;
/**
* 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.
*
* When a stack is first created, it contains no items.
*
* @author Jonathan Payne
* @version 1.24, 02/02/00
* @since JDK1.0
*/
public class Stack extends Vector
{
/**
* Creates an empty Stack.
*/
public Stack() { }
/**
* Pushes an item onto the top of this stack. This has exactly
* the same effect as:
*
* addElement(item)
*
* @param item the item to be pushed onto this stack.
* @return the item argument.
* @see java.util.Vector#addElement
*/
public Object push(Object item) {
return null;
}
/**
* Removes the object at the top of this stack and returns that
* object as the value of this function.
*
* @return The object at the top of this stack (the last item
* of the Vector object).
* @exception EmptyStackException if this stack is empty.
*/
public synchronized Object pop() {
return null;
}
/**
* Looks at the object at the top of this stack without removing it
* from the stack.
*
* @return the object at the top of this stack (the last item
* of the Vector object).
* @exception EmptyStackException if this stack is empty.
*/
public synchronized Object peek() {
return null;
}
/**
* Tests if this stack is empty.
*
* @return true if and only if this stack contains
* no items; false otherwise.
*/
public boolean empty() {
return false;
}
/**
* Returns the 1-based position where an object is on this stack.
* If the object o occurs as an item in this stack, this
* method returns the distance from the top of the stack of the
* occurrence nearest the top of the stack; the topmost item on the
* stack is considered to be at distance 1. The equals
* method is used to compare o to the
* items in this stack.
*
* @param o the desired object.
* @return the 1-based position from the top of the stack where
* the object is located; the return value -1
* indicates that the object is not on the stack.
*/
public synchronized int search(Object o) {
return 0;
}
/** use serialVersionUID from JDK 1.0.2 for interoperability */
private static final long serialVersionUID = 1224463164541339165L;
}