Given Below Is The Node Class To Perform Basic List Operations #115

Given below is the Node class to perform basic list operations and a Stack class with a no arg constructor.<br /> Select from the options the appropriate pop() operation that can be included in the Stack class. Also ‘first’ is the top-of-the-stack.</p> <pre><code class="language-java"> class Node { protected Node next; protected Object ele; Node() { this(null,null); } Node(Object e,Node n) { ele=e; next=n; } public void setNext(Node n) { next=n; } public void setEle(Object e) { ele=e; } public Node getNext() { return next; } public Object getEle() { return ele; } } class Stack { Node first; int size=0; Stack() { first=null; } }</code></pre>

This multiple choice question (MCQ) is related to the book/course gs gs121 Data Structures and Algorithms. It can also be found in gs gs121 Abstract Data Types - Stack using Linked List - Quiz No.1.

 class Node { protected Node next; protected Object ele; Node() { this(null,null); } Node(Object e,Node n) { ele=e; next=n; } public void setNext(Node n) { next=n; } public void setEle(Object e) { ele=e; } public Node getNext() { return next; } public Object getEle() { return ele; } }  class Stack { Node first; int size=0; Stack() { first=null; } }

 public Object pop() { if(size == 0) System.out.println("underflow"); else { Object o = first.getEle(); first = first.getNext(); size--; return o; } }

 public Object pop() { if(size == 0) System.out.println("underflow"); else { Object o = first.getEle(); first = first.getNext().getNext(); size--; return o; } }

 public Object pop() { if(size == 0) System.out.println("underflow"); else { first = first.getNext(); Object o = first.getEle(); size--; return o; } }

 public Object pop() { if(size == 0) System.out.println("underflow"); else { first = first.getNext().getNext(); Object o = first.getEle(); size--; return o; } }