Lecture 18 Objectives [Nov 28]prev next

ART MOMENT: .
 

The John Chandler Bancroft collection [Worcester Art Museum] of some 3,000 Japanese prints is internationally renowned.

At the end of today's class you should

HAVE READ:

• Readings on Exceptions

KNOW:

• the concept of an Exception
• the three kinds of Exception: (a) CheckedException; (b) Error; (c) Unchecked Exception
• the "Catch or Specify Requirement" [cite]
• how to throw an Exception [cite]
• how to catch an Exception
• the structure of a try { ... } catch (Exception e) { ... }

BE ABLE TO:

• Explain the following statement: "If a client can reasonably be expected to recover from an exception, make it a checked exception. If a client cannot do anything to recover from the exception, make it an unchecked exception". [cite]

DAILY QUESTION:

• Please note that this question is different from the Daily Question for Monday November 27th.
• This question asks you to consider the same NumberNode and NumberList that you saw on Exam 2. Here they are:
  
   

  /** Node class representing an integer. */ public class NumberNode {   int          value;    /* node value. */   NumberNode   next;     /* next one. */   public NumberNode (int i) {     value = i;     next = null;   } }

  /** List of numbers. */ public class NumberList {   NumberNode head;  /* first one. */   /** prepend a NumberNode with i to the front of the list. */   public void add (int i) { … } }

  Consider that you are shown the following method in the NumberList class:

  /** Method in NumberList. */ public void doAnotherThing() {    // prepend 3, then 5, then 7 to construct the list {7, 5, 3}    add (3);    add (5);    add (7);    NumberNode node = head;    head = head.next;    node.next = head;    head = head.next;    head.next = node;    node.next = null;  }

  What is the resulting list? Much of HW4 focused on your ability to perform such low-level manipulation of linked lists. You need to be able to understand the impact of these statements above.

  
  
  
  
  
   

Sample Exam question(s)