CHAPTER 7 ASSIGNMENT - LEARN JAVA BY EXAMPLE

Exercise 11-1. Create a base class, Telephone, and derive a class ElectronicPhone from it. In Telephone, create a protected string member phonetype, and a public method Ring( ) that outputs a text message like this: "Ringing the ." In ElectronicPhone, the constructor should set the phonetype to "Digital." In the Run( ) method, call Ring( ) on the ElectronicPhone to test the inheritance.
Exercise 11-2. Extend Exercise 11-1 to illustrate a polymorphic method. Have the derived class override the Ring( ) method to display a different message.
Exercise 11-3. Change the Telephone class to abstract, and make Ring( ) an abstract method. Derive two new classes from Telephone: DigitalPhone and TalkingPhone. Each derived class should set the phonetype, and override the Ring( ) method.


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