package com.coding.basic;
import java.util.EmptyStackException;
import javax.lang.model.element.QualifiedNameable;
public class Stack {
private ArrayList elementData = new ArrayList();
public void push(Object o){
elementData.add(o);
}
public Object pop(){
checkIsEmpty();
return elementData.remove(size()-1);
}
private void checkIsEmpty() {
if (isEmpty()){
throw new EmptyStackException();
}
}
public Object peek(){
checkIsEmpty();
return elementData.get(size()-1);
}
public boolean isEmpty(){
return elementData.size()==0;
}
public int size(){
return elementData.size();
}
public static void main(String[] args) {
Stack que = new Stack();
que.push(10);
que.push(11);
que.push(12);
System.out.println(que.peek());
System.out.println(que.isEmpty());
System.out.println(que.pop());
System.out.println(que.pop());
que.pop();
System.out.println(que.isEmpty());
}
}