What are Classes and Objects What is their difference?

Beran Santur — Tue, 02 Mar 2021 09:51:27 +0000

Class

Classes are just blueprints. That's all.

They are a data type -user defined- just like String.

They have attributes (data) and they have methods (functions)

They can hide data and methods which are only used internally in class.

Objects

If classes are blueprints, objects are the buildings that made from those blueprints.

They carry all the data and methods class has. So they are created from classes and they represent them.

They all can have a different identity for example Car is a class but Audi is an object.

Class: Fruit Object: Apple, Banana, Mango, Guava etc..

Difference between Objects and Classes

Classes are just defination of objects they are just templates or blueprints of objects whereas objects are instances of classes.

Classes is declared once but objects can be created multiple times.

Class is a logical entites but objects are physical entities.

Objects allocates memory when its created, on the contrary classes don't allocate memory when its created(memory is taken up for class definitions isn't on the stack nor heap. When you create an object of a class it will always go on either the stack or heap. Class declaration tells the compiler and runtime how much memory to allocate for each class instance, but only when requested.).

What is Object Oriented Programming?

Beran Santur — Tue, 02 Mar 2021 09:31:40 +0000

Object Oriented Programming is a basically abstraction method. It give us more modularized data.

For instance if we need to know whether a student registered a lesson, we could use procedural programming and we would create another function to check it. And I would perfectly work well but the thing is if somehow this logic changes it might affect the whole program provided we used that registering information in somewhere.

On the other hand if we used oop instead of procedural programming, we just had to create another function in the class. And we would achieve it with a precise change.

It gives us more reuseability, easy to maintain, easy to fix, easy to debug and easy to test.

Limitations

In little applications that won’t exist for long it is probably a better idea to use procedural programming since it oop makes program more larger in size and -since there is a lot in behind the scenes -, slower. But this is not particularly the case for C++ since it’s most efficient oop language out there.

DEV Community: Beran Santur

What are Classes and Objects What is their difference?

What is Object Oriented Programming?