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C++ program to convert octal number to hexadecimal using class

Submitted by Shubh Pachori, on August 22, 2022

Problem statement

Given an octal number, we have to convert it using the class and object approach.

Example:

Input:
Enter Octal Number: 56

Output:
Hexadecimal: 2e

C++ code to convert octal number to hexadecimal using the class and object approach

#include <iostream>
using namespace std;

// create a class
class OctalToHexa {
  // private data member
  private:
    int octal;

  // public functions
  public:
    // getOctal() function to get 
    // the octal number
    void getOctal() {
      cout << "Enter Octal Number:";
      cin >> octal;
    }

  // OToH() function to convert octal 
  // to hexadecimal
  string OToH() {

    // int type variables for operations
    int decimal = 0, remain;

    // Initializing base value to 1
    int base = 1;

    // Initializing Temporary variable 
    // and assigning octal into it
    int temp = octal;

    // while loop to convert 
    // octal number to decimal
    while (temp) {

      // Extracting last digit
      remain = temp % 10;

      // dividing temp by 10 to discard 
      // the last digit
      temp = temp / 10;

      //  Multiplying remain with base 
      // value and adding it to decimal
      decimal = decimal + remain * base;

      // multiplying base by 8 at every iteration
      base = base * 8;
    }

    // Initializing a char array hexa of length 
    // 100 to store hexadecimal value
    char hexa[100];

    //  counter for hexadecimal
    //  number array
    int index_1 = 0;

    // while loop to convert decimal value 
    // to hexadecimal value
    while (decimal != 0) {

      //  Temporary variable to
      //  store remainder
      int temp = 0;

      //  Storing remainder in
      //  temp variable.
      temp = decimal % 16;

      //  Check if temp < 10
      if (temp < 10) {

        // assigning temp with addition of 
        // 48 in the hexa array
        hexa[index_1] = temp + 48;

        // increment of 1 in the index_1
        index_1++;
      }

      // else it comes in else part
      else {

        // assigning temp with addition of 
        // 87 in the hexa array
        hexa[index_1] = temp + 87;

        // increment of 1 in the index_1
        index_1++;
      }

      // dividing decimal by 16
      decimal = decimal / 16;
    }

    // string type variable to store the 
    // reverse of the hexa array 
    string hexadecimal = "";

    //  Printing hexadecimal number array
    //  in reverse order
    for (int index_2 = index_1 - 1; index_2 >= 0; index_2--) {

      // copying reverse of hexa in hexadecimal
      hexadecimal = hexadecimal + hexa[index_2];
    }

    // returning hexadecimal
    return hexadecimal;
  }
};

int main() {
  // create an object
  OctalToHexa O;

  // string type variable to store 
  // hexadecimal value
  string hex;

  // function is called by the object to 
  // input octal number
  O.getOctal();

  // OToH() function to convert octal 
  // into hexadecimal
  hex = O.OToH();

  cout << "Hexadecimal:" << hex;

  return 0;
}

Output

Enter Octal Number:3344
Hexadecimal: 6e4

Explanation

In the above code, we have created a class OctalToHexa, one int type data member octal to store the octal number, and public member functions getOctal() and OToH() to store and convert the given octal number to hexadecimal.

In the main() function, we are creating an object O of class OctalToHexa,  reading the octal number given by the user using getOctal() function, and finally calling the OToH() member function to convert the given octal number. The OToH() function contains the logic to convert the given octal number to hexadecimal number and printing the result.

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