Abstract Classes

Abstract Classes

1. What are they?

   • this class is the superclass, it CANNOT be instantiated. Subclasses are derived from them.
     • Although it CANNOT be instantiated it can have constructors.

2. **IF A METHOD IS ABSTRACT IN AN ABSTRACT CLASS IT MUST BE OVERRIDEN IN THE CHILD CLASS

3. Object is not an abstract class

4. Rules:

   • 1. You CANNOT instantiate an abstract class.
     • 2. Abstract classes CAN have concrete methods
       • 3. A subclass CAN be abstract even if the super isn't
         • 4. A class CAN override a method & make it abstract

5. Examples:

   • public abstract class Animal {}
     • public abstract void makeNoise() {}
       • Must be overriden in subclass/child class.