Java Tutorial: Introduction to Object Oriented Programming

• Object-Oriented Programming tries to map code instructions with real-world, making the code short and easier to understand.
• With the help of OOPs, we try to implement real-world entities such as object, inheritance, abstraction, etc.
• OOPs helps us to follow the DRY(Don't Repeat Yourself) approach of programming, which in turn increases the reusability of the code.

Two most important aspects of OOPs - Classes & Objects :

Class :

• A class is a blueprint for creating objects.
• Classes do not consume any space in the memory.
• Objects inherit methods and variables from the class.
• It is a logical component.

Objects :

• An object is an instantiation of a class. When a class is defined, a template (info) is defined.
• Every object has some address, and it occupies some space in the memory.
• It is a physical entity.
• Take a look at the below example to get a better understanding of objects and classes :

How to model a problem in OOPs

• We identify the following:

Noun              - Class                        - Employee
Adjective         - Attributes                   - name, age, salary
Verb              - Methods                      - getSalary(), increment()

• This is all for this tutorial. We will do a detailed discussion on every aspect of OOPs in further tutorials.

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