Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Inheritance in Java Inheritance in Java Abstracting Abstract Classes

Posted by Maryam Kamar
Maryam Kamar
2,549 Points

i understood the concept, but can't we just make everything in the animal class abstract then? e.g. makeSound()

...since each animal makes a different sound anyway so what's the point of not making everything abstract?

Caleb Kemp
Caleb Kemp
12,754 Points
Caleb Kemp
Caleb Kemp
12,754 Points

I can think of two possible reasons why a developer might not want an abstract class makeSound() for the animal class.

  1. Your code never requires the animals to make sound, making the makeSound() method unnessesary.

  2. Like how the auto class was separated into motorcycles and cars subclasses, you might also want to separate the animal class into soundAnimals and quietAnimals (for animals that don't make sounds such as Sea Urchins). In that case, you would probably only want soundAnimals to have the makeSound() method.

In many cases creating a makeSound() abstract class for the animal class would be a great idea. I know you were just thinking aloud, but I thought you might want to hear what some possible exceptions might be. Hope it helps