
public class SmallClass implements InterfaceA
{

   class definition body

}

Answer:

Yes, the definition is correct. You might wonder that it does not extend a base class, but it does.

If no other class is extended, Object is the base class. SmallClass extends Object and implements InterfaceA.

Example Problem

Let us create a database program for a store. The store sells:

Goods, each of which has the attributes:
- description
- price
The types of goods are:
- Food — with an attribute calories. Food objects are not taxable.
- Toy — with an attribute minimumAge. Toy objects are taxable.
- Book — with an attribute author. Book objects are taxable.

There are many things that are taxable that are not goods, such as services or entertainment. Also, not all goods are taxable. So we want to have the concept taxable as a separate concept, not part of the concept of Goods. Here is what the concept Taxable looks like:

A Taxable item,
- has a taxRate of 6 percent,
- has a calculateTax() method.

When implemented in Java, these concepts will appear as a class hierarchy and as an interface.

Concept	Parent Class, Child Class, or Interface?
Goods
Food
Toy
Book
Taxable

Answer:

Example Problem

QUESTION 6: