OOP

Question 1

What are constructors?

Answer 1

They are a special kind of method that plays the role of initializing objects?

Question 2

Constructors vs methods

Answer 2

Constructors: Initialize and object’s state
Methods: Used to exhibit functionality of an object.

Question 3

What are their 3 peculiarities(constructors)

Answer 3

They have the same name as the class itself
They do not have a return type -- not even void
Invoked using the new operator when an object is created

Question 4

Method overloading

Answer 4

Multiple methods can have the same name with different paramters.

Question 5

Instance vs Static class members

Answer 5

Static: Can be invoked directly from their class

Question 6

Adv of OOP

Answer 6

Modularization
Encapsulation
Understandability
Maintenance

Question 7

Public vs Private

Answer 7

Public: Access modifier visible to all classes in any package
Private: Access modifier visible only to declared class.

Question 8

Objects

Answer 8

An object is an entity in the real world. An object has:
A unique identity,
state(Also known as properties or attributes)
behaviour(Methods): What the object can do.

Question 9

Classes

Answer 9

Objects of the same type are defined using a common class
A class is a template or blueprint that defines the properties and behaviours for objects.

Question 10

What does a class use

Answer 10

Variables to define the state
methods to define behaviors
Constructors to perform initializing actions

Question 11

Access modifiers

Answer 11

Used for controlling levels of access class members in Java