import stackqueue.*; public class TestStackQueue { public static void main(String[] args) { Stack x = new Stack(); x.push("cat"); x.push(new Integer(71)); x.push(new Double(3.14)); System.out.println(x.peek()); x.pop(); System.out.println(x.peek()); System.out.println(x.peek()); System.out.println(x); System.out.println(); Queue y = new Queue(); y.enqueue("dog"); y.enqueue(new Integer(46)); y.enqueue(new Character('f')); y.dequeue(); System.out.println(y.getFront()); System.out.println(y.getBack()); System.out.println(y); } }