package task01;
/**第一周作业
* 自己实现一个 栈
* Created by eurry on 2017/2/26.
*/
public class Stack {
private ArrayList elementData= new ArrayList();
public void push(Object o){
elementData.add(o);
}
public Object pop(){
return elementData.remove(elementData.size()-1);
}
/**
*查看栈顶对象而不移除它
*/
public Object peek(){
return elementData.get(elementData.size()-1);
}
public boolean isEmpty(){
return elementData.size()==0;
}
}