QUESTION 24:
Can a class extend an interface?
No. private would mean that nobody could use it, which is not sensible.
An interface can be an extension of another interface (but not an extension of a class):
public interface ExciseTaxable extends Taxable
{
double extraTax = 0.02;
double calculateExtra();
}
A complex hierarchy of interfaces can be constructed using this feature. This is an advanced feature which you will probably not need to use.
Can a class extend an interface?