🟣 OOP · Lesson 38

Classes and Objects

What is Classes and Objects?

Classes and Objects
A class is a blueprint and an object is an instance created from that blueprint. Classes combine data members and member functions.

Level
🟣 Object-Oriented Programming

Example File
classes-objects.cpp

Main Focus
Concept + syntax + practical C++ program

Why should you learn this?

It helps you write correct and readable C++ programs.
It is used repeatedly in school practicals, projects and competitive programming.
It builds the base for advanced topics such as OOP, STL and data structures.

Important Terms

Term	Meaning / Use
class	Classes and Objects programming में Class use होता है।
object	Classes and Objects programming में Object use होता है।
data member	Classes and Objects programming में Data member use होता है।
member function	Classes and Objects programming में Member function use होता है।
instance	Classes and Objects programming में Instance use होता है।

Syntax / Pattern

C++

class ClassName { members; }; ClassName obj;

Example Program

main.cpp

#include <iostream>
using namespace std;
class Account{
public:
    int balance = 5000;
    void show(){ cout << balance; }
};
int main(){
    Account a;
    a.show();
    return 0;
}

Expected Output

5000

Program Explanation

Account defines structure and behavior.
a is an object of Account.

Exam Tip: In C++ practical answers, write the logic first, then the program, then expected output. For theory, always include one suitable example.

Where will you use it?

bank account
student profile
product record

Common Mistakes

Forgetting semicolon after class.
Calling non-static member without object.

Practice Tasks

Create class Student with roll and name.
Create two objects and print data.

Summary

Classes and Objects एक ज़रूरी C++ topic है। परिभाषा सीखें, syntax समझें, example program चलाएं और फिर practice tasks हल करके concept मज़बूत करें।