Week 5 Hierarchy, Inheritance, Superclasses and Subclasses

Inheritance goes from generalised to specialised. t/f?

True

Describe inheritance using the is-a relationship concept

means that one class is a subclass of another. For example, a dog is a mammal, in other words a Dog class is a subclass of Mammals class.

descri aggregation using the has-a relationship concept

a dog has a leg (usually more than one). If in class Dog we declare a member variable of type Leg (another class) we don’t have inheritance, we have a has-a relationship (aggregation).

can we combine is-a and has-a relationships?

yes eg:, a dog is-a mammal and it has-a leg/s

What does a subclass constructor look like

public class Dog extends Mammals {private Leg [] legs; /* Leg is a class and legs is an array of objects of this type */ ...}

Does a subclass inherit all members of its parent class and predecesorclasses?

No, private variables and methods are not inherited.

what is the word super used for?

to refer hidden variables and overridden methods of the superclass

When can a subclass directly access super class members

if they are declared publoc protected or default and are in the same package

does a subclass inherit data fields automatically?

yes