C++ Programming – Quick Review (Simple & Easy Guide)

This blog explains C++ programming step by step in very simple English. Each topic is explained clearly, so even beginners can understand easily. Useful for students, freshers, and interviews.

1. What is C++?

C++ is a programming language used to create software.

It is an extension of C language
Created by Bjarne Stroustrup
C++ supports Object-Oriented Programming (OOP)

👉 In simple words: C++ helps us tell the computer what to do in a fast and powerful way.

2. Why Learn C++?

Very fast language
Used in games, browsers, operating systems
Important for interviews
Helps understand other languages easily

3. Basic Structure of C++ Program

#include <iostream>
using namespace std;

int main() {
    cout << "Hello World";
    return 0;
}

Simple explanation:

#include <iostream> → used for input and output
using namespace std → allows using cout and cin
main() → program starts from here
cout → prints output on screen

4. Tokens in C++

Tokens are the smallest parts of a C++ program.

Examples:

Keywords (int, if)
Variables (age, num)
Operators (+, =)

👉 Without tokens, a program cannot be written.

5. Keywords

Keywords are reserved words.
They have a special meaning and cannot be used as variable names.

Examples:

int, float, if, else, for, while, class, return

6. Variables

Variables are used to store values.

int age = 20;

👉 Here, age stores value 20.

7. Data Types

Data types tell the computer what type of data we are storing.

Data Type	Meaning
int	Whole numbers
float	Decimal numbers
double	Large decimal values
char	Single character
bool	True or False

8. Input and Output (cin & cout)

Output

cout << "Welcome";

Prints text on screen.

Input

int num;
cin >> num;

Takes input from user.

9. Operators

Operators are used to perform operations.

Types:

Arithmetic: + - * / %
Relational: > < == !=
Logical: && || !
Assignment: =

10. Conditional Statements

Used to make decisions.

if statement

if(age >= 18) {
    cout << "Adult";
}

👉 If condition is true, code runs.

if-else

if(num % 2 == 0)
    cout << "Even";
else
    cout << "Odd";

11. Switch Statement

Used when there are many choices.

switch(choice) {
    case 1: cout << "One"; break;
    default: cout << "Invalid";
}

12. Loops

Loops repeat code again and again.

for loop

for(int i = 1; i <= 5; i++) {
    cout << i;
}

while loop

while(i <= 5) {
    i++;
}

13. Arrays

Arrays store multiple values in one variable.

int marks[3] = {10, 20, 30};

14. Strings

Strings store text.

string name = "C++";

15. Functions

Functions are blocks of code that perform a task.

void greet() {
    cout << "Hello";
}

👉 Helps avoid repeating code.

16. Object-Oriented Programming (OOP)

OOP is a way of programming using objects and classes.

Main concepts:

Class
Object
Inheritance
Polymorphism

17. Class and Object

class Student {
public:
    int id;
    string name;
};

👉 Class is a blueprint, object is real.

18. Constructor

Constructor runs automatically when object is created.

class Test {
public:
    Test() {
        cout << "Constructor called";
    }
};

19. Inheritance

Inheritance allows one class to use another class features.

class B : public A {
};

20. Polymorphism

Same function name, different behavior.

virtual void show();

21. Pointers

Pointers store memory address.

int *p = &a;

22. File Handling

Used to store data in files.

ofstream file("data.txt");
file << "Hello";
file.close();

23. Advantages of C++

Fast
Object-oriented
Used in real projects

24. Disadvantages of C++

Syntax is complex
Hard for beginners

Conclusion

C++ is a powerful and important language. Learning C++ builds strong programming basics and helps in interviews.