Relationships - Day 4

Question 1

3 ways to associate relationships between two classes

Reuse members of a class in another

Answer 1

Aggregation

Association

Inheritance

Question 2

Association

Answer 2

Uses-a relationship

I.e Patient makes an appointment Vs A driver uses a car

Association is represented by an arrow in a class diagrams.

Question 3

Aggregation

Answer 3

“Has a” type of relationship

Question 4

Inheritance

Answer 4

“Is a” relationship.

Can have multiple sub classes.

When a class inherits from another class

Question 5

Inheritance hierarchy

Answer 5

Parent class
^
|
Child class

Parents have multiple children

Question 6

Inheritance of private, public etc.

Answer 6

Static and private cannot be inherited

No need for a parent type object with public inheritance

Question 7

Inheritance uses what keyword

Answer 7

Extend

Question 8

Super constructor

Answer 8

“super();” Has to be the first statement inside a constructor!

Question 9

Types of inheritance

Answer 9

Single inheritance

Multilevel inheritance

Hierarchical inheritance

Multiple inheritance

Question 10

Single inheritance

Answer 10

One class is extended by one class

Question 11

Multilevel inheritance

Answer 11

A class extends another class which extended another class

Grandad - dad - son

Question 12

Hierarchical inheritance

Answer 12

Multiple classes extend the same base class

Question 13

Multiple inheritance

Answer 13

One class extends multiple classes.

Class 1 Class 2

(Don’t have to know this one as it’s not supported in Java)