Adding Two Numbers Program

Introduction

In this lab, you will learn how to write a basic program to add two numbers in C++ programming language. You will also learn about variable declaration, initialization, input/output operations, and basic mathematical operations in C++.

Skills Graph

Variable Declaration

First, declare two variables a and b of integer type, to store the user input. Also, declare a variable sum and initialize it with 0.

#include<iostream>

using namespace std;

int main()
{
    //variable declaration
    int a, b;

    //variable declaration and initialization
    int sum=0;

    //...
}

User Input

Take input from the user using cin and cout statements. cout is used to display the message to the user, cin is used to accept the input from the user.

cout << "\n\nWelcome to LabEx :-)\n\n\n";
cout << " =====  Program to add 2 numbers ===== \n\n";

cout << "Enter the first Number : ";
cin >> a;

cout << "\nEnter the second Number : ";
cin >> b;

Addition of Two Numbers

Add the two numbers a and b and store the result in the variable sum.

//Adding the two numbers
sum = a + b;

Display the Result

Display the result to the user using cout statement.

//displaying the final output (sum)
cout << "\nAddition of the two numbers is : " << sum;

Compile and Run the Program

Compile the program using the following command in terminal:

g++ ~/project/main.cpp -o main

Run the program using the following command in the terminal:

./main

Verify the Output

After running the program, you should see the output in the terminal:

Welcome to LabEx :-)


 =====  Program to add 2 numbers =====

Enter the first Number : 10

Enter the second Number : 20

Addition of the two numbers is : 30

Summary

In this lab, you learned how to write a basic C++ program to add two numbers. You also learned about variable declaration, initialization, user input/output, and basic mathematical operations in C++. You can now try out other mathematical operations or modify the program to suit your needs.

Here is the complete code for the main.cpp file:

#include<iostream>

using namespace std;

int main()
{
    //variable declaration
    int a, b;

    //variable declaration and initialization
    int sum=0;

    //take user input
    cout << "\n\nWelcome to LabEx :-)\n\n\n";
    cout << " =====  Program to add 2 numbers ===== \n\n";

    cout << "Enter the first Number : ";
    cin >> a;

    cout << "\nEnter the second Number : ";
    cin >> b;

    //Adding the two numbers
    sum = a + b;

    //displaying the final output (sum)
    cout << "\nAddition of the two numbers is : " << sum;

    return 0;
}