oop

Question 1

what is an object

Answer 1

An object is
* Something tangible (person, pen, mug

An object has state, behavior, identity

Question 2

What is a class

Answer 2

A class is a blueprint or template for creating objects (instances). It
defines the structure and behaviour that its instances (objects) will
have.

Question 3

Constructors

Answer 3

The constructor MUST have the same name as
the class name
* A class can have more than one constructor

Question 4

instance variable

Answer 4

An instance variable can hold a single value
 e.g. private double balance

Instance variables are typically defined as private
 this facilitates information hiding between classes
 more on access modifiers (e.g. private) later
 information hiding essential in industry

Question 5

instance Methods

Answer 5

• Instance methods represent the behavior and alter
  the state of an object, they manipulate an object
• Instance methods also provide the interface of
  classes
   different objects can communicate with each other via
  their instance methods
• To achieve this, instance methods are typically
  defined as public
   can be accessed by members of other classes

Question 6

Method overloading

Answer 6

Instance methods can be overloaded, i.e. more than one
method can have the same name inside the same class
* For this to work, overloaded methods must have different
number of parameters, or parameters of different types

public void deposit(double amount)
public void deposit(double money)
2) public void deposit(double amount)
public void deposit(double amount, double interest

Question 7

Access modifier

Answer 7

The declaration of an instance variable, a constructor, an
instance method (even of a class) begins with an access
modifier (public or private)
 Public: the entity can be accessed by other classes
 Private: the entity is only accessible from within the class
itself