package com.java.gsl;
public class Stack {
private ArrayList elementData = new ArrayList();
public void push(Object o){
elementData.add(o);
}
public Object pop(){
int i = elementData.size();
elementData.remove(i);
return elementData.get(i);
}
public Object peek(){
int i = elementData.size();
return elementData.get(i);
}
public boolean isEmpty(){
return elementData.size()>0;
}
public int size(){
return elementData.size();
}
}