View Full Document


Unformatted text preview:

Chapter 8 Inheritance Lab Exercises Topics Lab Exercises Inheritance Exploring Inheritance A Sorted Integer List Test Questions Overriding the equals Method Adapter Classes Extending Adapter Classes Animation Rebound Revisited Count Down Chapter 8 Inheritance 151 Exploring Inheritance File Dog java contains a declaration for a Dog class Save this file to your directory and study it notice what instance variables and methods are provided Files Labrador java and Yorkshire java contain declarations for classes that extend Dog Save and study these files as well File DogTest java contains a simple driver program that creates a dog and makes it speak Study DogTest java save it to your directory and compile and run it to see what it does Now modify these files as follows 1 Add statements in DogTest java after you create and print the dog to create and print a Yorkshire and a Labrador Note that the Labrador constructor takes two parameters the name and color of the labrador both strings Don t change any files besides DogTest java Now recompile DogTest java you should get an error saying something like Labrador java 18 Dog java lang String in Dog cannot be applied to 1 error If you look at line 18 of Labrador java it s just a and the constructor the compiler can t find Dog isn t called anywhere in this file a What s going on Hint What call must be made in the constructor of a subclass b 2 Fix the problem which really is in Labrador so that DogTest java creates and makes the Dog Labrador and Yorkshire all speak Add code to DogTest java to print the average breed weight for both your Labrador and your Yorkshire Use the avgBreedWeight method for both What error do you get Why Fix the problem by adding the needed code to the Yorkshire class 3 Add an abstract int avgBreedWeight method to the Dog class Remember that this means that the word abstract appears in the method header after public and that the method does not have a body just a semicolon after the parameter list It makes

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...

Join to view Inheritance and access 3M+ class-specific study document.

We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Inheritance and access 3M+ class-specific study document.


By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?