Stackimplement.java

import java.util.*;
public class Stackimplement {
    static class Stack{
        static ArrayList<Integer> list = new ArrayList<>();
        
        //function to check stack is empty or not
        public static boolean isEmpty(){
            return list.size() == 0;
        }

        //push..
        public static void push(int data){
            list.add(data);
        }

        //pop..
        public static int pop(){
            int top = list.get(list.size()-1);
            list.remove(list.size()-1);
            return top;
        }

        //peek..
        public static int peek(){
            return list.get(list.size()-1);
        }
    }
    public static void main(String args[]){
        Stack s = new Stack();
        s.push(1);
        s.push(2);
        s.push(3);

        while(!s.isEmpty()){
            System.out.println(s.peek());
            s.pop();
        }

    }
}