Lab 7.1 — An Extended Phone Number Class (ExtendedPhoneNumber)

Overview

Create a subclass of the PhoneNumber class of Lab 4 named ExtendedPhoneNumber. The subclass should add a description (String) for the phone number, e.g., "mobile", "home", etc (the description is arbitrary.

• You can do this directly in CodeLab or develop it first in your IDE.
• I've provide you with the PhoneNumber class as well as a sample app for testing (and the output). (see link at bottom of page)

Implementation Details

In addition to the instance variable, you should have:

• a getDescription method
• the usual (static) read method:
  • while it would be wonderful if this method could leverage the read method of PhoneNumber, that doesn't quite work. (If you are wondering why, think of leveraging the toString method of Counter in the toString of UpperBoundedCounter … the same issue arises).
  • Instead, have this new read method read in the description as well as the number. Both are passed to the constructor for ExtendedPhoneNumber which in turn passes the number up to 's constructor (using super).
• the toString method should call the toString of the superclass (PhoneNumber ans prefix it with the description (see the output below -- it's the phone number: line).

Here is the expected output:

phone number: mobile: (550)831-9463
description: mobile
area code: 550
exchange: 831
line number: 9463
is toll free: false

phone number: home: (775)087-0947
description: home
area code: 775
exchange: 087
line number: 0947
is toll free: false

phone number: work: (766)294-2999
description: work
area code: 766
exchange: 294
line number: 2999
is toll free: false

phone number: other: (342)775-1584
description: other
area code: 342
exchange: 775
line number: 1584
is toll free: false

---
4 phone numbers processed.

Submitting to CodeLab

• All you need to submit is the subclass, i.e., ExtendedPhoneNumber.java

Lab 7.2 — Fun With Polymorphism (ExtendedPhoneNumberApp)

Overview

Given the ExtendedPhoneNumber (and PhoneNumber) classes of the previous lab, code the following app:

• Declare an array of PhoneNumber (100 elements is more than enough)
• Populate the arrays with ExtendedPhoneNumbers read in from the file "extended_numbers.text" (using the read method). Print the objects out as you read them in .
• Continue populating the array (at the end) with PhoneNumers read in from the file "numbers.text". Again, print the objects out as you read them in.
• Print out the array (I write a toString method that took the array and size and built a String representing the array (the logic was just like a regular toString; but this one is not the 'official' toString (this is an app class after all, not an object class; in fact, there's no reason not to declare this method static there are not instance variables used … the atrray and size are passed in as arguments).
  • Feel free to simply write a prnt method that goes straight out to System.out (though that is not reallt 'the Java way').
• Sort the array using bubble sort (again I wrote a sort method, you can do it in place if you'd rather).
  • I've added a compareTo medthod to the PhoneNumber class for the purpose of sorting
• Print the array again.

Here is the expected output:

mobile: (550)831-9463
home: (775)087-0947
work: (766)294-2999
other: (342)775-1584

(718)123-4567
(347)987-6543

Before sorting: {mobile: (550)831-9463, home: (775)087-0947, work: (766)294-2999, other: (342)775-1584, (718)123-4567, (347)987-6543}


After sorting: {other: (342)775-1584, (347)987-6543, mobile: (550)831-9463, (718)123-4567, work: (766)294-2999, home: (775)087-0947}

I've provided the sample input files as well as the expected out here as well. If you develop in your IDE, use your own ExtendedPhoneNumber class from the previous lab.

Submitting to CodeLab

• All you need to submit is the app, I provide the other two classes.