Some Basic C++ Programs

Program 1: Program To Add Two Numbers

#include <iostream>
using namespace std;

int main()
{
    int firstNumber, secondNumber, sumOfTwoNumbers;
    
    cout << "Enter two integers: ";
    cin >> firstNumber >> secondNumber;

    // sum of two numbers in stored in variable sumOfTwoNumbers
    sumOfTwoNumbers = firstNumber + secondNumber;

    // Prints sum 
    cout << firstNumber << " + " <<  secondNumber << " = " << sumOfTwoNumbers;     

    return 0;
}

Output

Enter two integers: 4 
5 
4 + 5 = 9

In this program, user is asked to enter two integers. These two integers are stored in variables firstNumber and secondNumber respectively.

Then, the variables firstNumber and secondNumber are added using + operator and stored in sumOfTwoNumbers variable.

Finally, sumOfTwoNumbers is displayed on the screen.

Program 2: C++ Program To Reverse An Integer

#include <iostream>
using namespace std;

int main()
{
    int n, reversedNumber = 0, remainder;

    cout << "Enter an integer: ";
    cin >> n;

    while(n != 0)
    {
        remainder = n%10;
        reversedNumber = reversedNumber*10 + remainder;
        n /= 10;
    }

    cout << "Reversed Number = " << reversedNumber;

    return 0;
}

Output

Enter an integer: 12345
Reversed number = 54321

This program takes an integer input from the user and stores it in variable n.

Then the while loop is iterated until n != 0 is false.

In each iteration, the remainder when the value of n is divided by 10 is calculated, reversedNumber is computed and the value of n is decreased 10 fold.

Finally, the reversedNumber (which contains the reversed number) is printed on the screen.