Chapter 5

Question 1

What is multiple inheritance

Answer 1

A class inherited by more than one class

Question 2

What is diamond problem

Answer 2

In multiple inheritance, if intermediate classes inheriting from same base class then the 3rd level of child class will have same behavior from two classes. It is called diamond problem.C++ gives solution to it that inheritance should be from only any one root.

Question 3

What is association in OO

Answer 3

object interaction with each other is called association

Question 4

What are 2 main types of associations

Answer 4

• Class association (inheritance)
• Object association (simple association, composition, aggregation)
  Note: object must have reference of one another.

Question 5

What is simple association

Answer 5

It is the weakest link between objects. It is the reference by which one object can interact with some other object.

Question 6

What are sub types of simple association

Answer 6

w. r.t. navigation
- One-way association (single direction)
- Two-way association (both direction)
w. r.t. number of objects
- Binary association (2 objects interact)
- Ternary association (3 objects interact)
- N-ary association (more than 3 objects interact)

Question 7

What is composition

Answer 7

An object may be composed of other smaller objects. It is called composition. Smaller objects are part of main object and it is strong relationship. A smaller object can not sustain independently. The relationship between objects is whole-part.

Question 8

What is aggregation

Answer 8

An object may contain a collection of other objects. The relationship between the contained objects and container object is called aggregation. It is a weak relationship because aggregate object is not part of container and it can exist independently.