🟢 Foundation · Lesson 08

Input and Output in C++

What is Input and Output in C++?

Input and Output in C++
Input allows a program to receive data from the user, and output displays information on the screen. C++ mainly uses cin for input and cout for output.

Level
🟢 Beginner – C++ Foundation

Example File
input-output.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
cin	Cin used in Input and Output in C++ programming.
cout	Cout used in Input and Output in C++ programming.
insertion operator	Insertion operator used in Input and Output in C++ programming.
extraction operator	Extraction operator used in Input and Output in C++ programming.
endl	Endl used in Input and Output in C++ programming.

Syntax / Pattern

cin >> variable; cout << value;

Example Program

#include <iostream>
using namespace std;

int main() {
    string name;
    int marks;

    cout << "Enter name and marks: ";
    cin >> name >> marks;

    cout << "Student: " << name << endl;
    cout << "Marks: " << marks;
    return 0;
}

Expected Output

Enter name and marks: Rahul 88 Student: Rahul Marks: 88

Program Explanation

cin reads values from keyboard.
>> sends input into variables.
<< sends output to screen.

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?

interactive programs
forms
calculators
menu-driven applications

Common Mistakes

Using cin for names with spaces without getline().
Forgetting variable before using cin.
Mixing cin and getline without handling newline.

Practice Tasks

Take two numbers and print their sum.
Take name using getline() and print welcome message.

Summary

Input and Output in C++ is an important C++ topic. Learn the definition, understand the syntax, run the example program and then solve the practice tasks to make the concept strong.