First In First Out

Source code : 

package fifo;

import java.util.*;

public class FIFO{
  public static void main(String[] args) {
  Stack stack=new Stack();
  stack.push(new Integer(10));
  stack.push("a");
  System.out.println("The contents of Stack is" + stack);
  System.out.println("The size of an Stack is" + stack.size());
  System.out.println("The number poped out is" + stack.pop());
  System.out.println("The number poped out is " + stack.pop());
  //System.out.println("The number poped out is" + stack.pop());
  System.out.println("The contents of stack is" + stack);
  System.out.println("The size of an stack is" + stack.size());
  }
}

Gambar output proses :