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C++ program to swap first and last digits of a number using class

Submitted by Shubh Pachori, on September 04, 2022

Problem statement

Given a number, we have to swap its first and last digits using the class and object approach.

Example:

Input:
Enter Number : 643745

Output:
Swapped Number : 543746

C++ code to swap first and last digits of a number using the class and object approach

#include <math.h>
#include <iostream>

using namespace std;

// create a class
class SwapNumber {
  // private data member
 private:
  int number;

  // public member functions
 public:
  // getNumber() function to insert 
  // the number
  void getNumber() {
    cout << "Enter Number : ";
    cin >> number;
  }

  // swapNumber() function to swap the first and
  // last digit of the inputted number
  int swapNumber() {
    // initializing int type variables to perform operations
    int last_digit, first_digit, digits, swapped;

    // finding the last digit of the number
    last_digit = number % 10;

    // finding total number of digits in number
    digits = (int)log10(number);

    // finding the first digit of the number
    first_digit = (int)(number / pow(10, digits));

    // copying last digit in swapped
    swapped = last_digit;

    // multiplying digits multiple of 10
    swapped = swapped * (int)pow(10, digits);

    // adding middle digits in the swapped
    swapped = swapped + number % ((int)pow(10, digits));

    // subtracting last digit from the swapped
    swapped = swapped - last_digit;

    // adding first digit in the swapped
    swapped = swapped + first_digit;

    // returning the swapped number
    return swapped;
  }
};

int main() {
  // create object
  SwapNumber S;

  // int type variable to store 
  // Swapped number
  int number;

  // calling getNumber() function to 
  // insert number
  S.getNumber();

  // calling swapNumber() function to 
  // swap digits
  number = S.swapNumber();

  cout << "Swapped Number : " << number << endl;

  return 0;
}

Output

Enter Number :1234
Swapped Number : 4231

Explanation

In the above code, we have created a class SwapNumber, one int type data member number to store the number, and public member functions getNumber() and swapNumber() to store the number and to swap last and first digits of the inputted number.

In the main() function, we are creating an object S of class SwapNumber, reading the number inputted by the user using getNumber() function, and finally calling the swapNumber() member function to swap last and the first digit of the inputted number. The swapNumber() function contains the logic to swap the last and first digits of the inputted number and printing the result.

C++ Class and Object Programs (Set 2) »