Understanding Inheritance and Encapsulation in Object Oriented Programming

In this unit, we will delve into two fundamental concepts of Object Oriented Programming (OOP): Inheritance and Encapsulation. These concepts are crucial for structuring and organizing code in an efficient and secure manner.

Inheritance

Inheritance is a mechanism that allows one class to acquire the properties (attributes and methods) of another. With the use of inheritance, information is made manageable in a hierarchical order.

The class which inherits the properties of another class is known as the subclass or child class, and the class whose properties are inherited is known as the superclass or parent class.

Inheritance supports the concept of reusability, i.e., we can add additional features to an existing class without modifying it. This is possible by deriving a new class from the existing one.

Types of Inheritance

There are several types of inheritance, namely:

1. Single Inheritance: When a class extends another class, it's known as single inheritance.
2. Multilevel Inheritance: When a class extends a class, which extends another class then it is called multilevel inheritance.
3. Hierarchical Inheritance: When a class is inherited by many subclasses, it's known as hierarchical inheritance.
4. Multiple Inheritance: When a class can inherit from more than one class, it's known as multiple inheritance.

Encapsulation

Encapsulation is defined as the wrapping up of data under a single unit. It is the mechanism that binds together code and the data it manipulates. In a different way, encapsulation is a protective shield that prevents the data from being accessed by the code outside this shield.

Technically in encapsulation, the variables or data of a class are hidden from any other class and can be accessed only through any member function of their class in which they are declared.

Encapsulation can be achieved by: Declaring all the variables in the class as private and writing public methods in the class to set and get the values of variables.

Benefits of Encapsulation

1. Data Hiding: The user will have no idea about the inner implementation of the class. It will not be visible to the user how the class is storing values in the variables. The user will only know that we are passing the values to a setter method and variables are getting initialized with that value.
2. Increased Flexibility: We can make the variables of the class as read-only or write-only depending on our requirement. If we wish to make the variables as read-only then we have to omit the setter methods like setName(), setAge(), etc. from the above program or if we wish to make the variables as write-only then we have to omit the get methods like getName(), getAge(), etc. from the above program.
3. Reusability: Encapsulation also improves the re-usability and easy to change with new requirements.
4. Testing code is easy: Encapsulated code is easy to test for unit testing.

By understanding and implementing inheritance and encapsulation, you can create more secure and organized code, improving the efficiency and functionality of your programming projects.