package stack;

import java.util.NoSuchElementException;

import java.util.Vector;

/**

* <p>A <strong>MyStringStack</strong> </p>

* is a class that implements a simple (LIFO) stack object. It makes use of the Vector {@link java.util.Vector}

* <p>It has four basic operations:

* <code>push()</code> to push an element onto the stack

* <code>pop()</code> to retrieve the last pushed element

* <code>isEmpty()</code> to verify whether the stack has no more elements

* <code>clear()</code> to empty the stack.

* </p>

* @author Swarnalatha Ashok

* @version 1.0 2008-07-16

* @since JDK 1.5

*/

public class MyStringStack {

private Vector<String> v = new Vector<String> ();

public void push (String newElement) {

if (newElement != null) v.add (newElement);

}

/**

* Returns a String object that was pushed the last on the stack.

* <p>This method always returns a valid String. </p>

* <p>If there is no element it throws a NoSuchElementException exception.</p>

*

* @return the String on top of the stack

* @throws NoSuchElementException if there are no elements on the stack

* @see String

*/

public String pop() throws NoSuchElementException {

//throw new NoSuchElementException();

String result = v.lastElement();

v.remove(result);

System.out.println("hello");

return result;

//return v.lastElement();

}

public boolean isEmpty() {

return v.isEmpty();

}

public void clear() {

v = new Vector<String> ();

}

}