Java OOP

Java - What is OOP?

OOP stands for Object-Oriented Programming.

Procedural programming is about writing procedures or methods that perform operations on the data, while object-oriented programming is about creating objects that contain both data and methods.

Object-oriented programming has several advantages over procedural programming:

• OOP is faster and easier to execute.
• OOP provides a clear structure for the programs.
• OOP helps to keep the Java code DRY (Don't Repeat Yourself), making the code easier to maintain, modify, and debug.
• OOP makes it possible to create fully reusable applications with less code and shorter development time.

Tip: The Don't Repeat Yourself (DRY) principle is about reducing the repetition of code. You should extract out the common code in the application, place it in a single location, and reuse it instead of repeating it.

Java - What are Classes and Objects?

Classes and objects are the two main aspects of object-oriented programming.

Look at the following illustration to see the difference between a class and objects:

Example 1:

Class: Fruit

Objects:

• Apple
• Banana
• Mango

Example 2:

Class: Car

Objects:

• Volvo
• Audi
• Toyota

So, a class is a template for objects, and an object is an instance of a class.

When individual objects are created, they inherit all the variables and methods from the class.

You will learn much more about classes and objects in the next chapter.