C++ Program to Convert Octal Number to Decimal and vice-versa
In this example, we will learn to convert octal number to decimal and decimal number to octal manually by creating a user-defined function.
To understand this example, you should have the knowledge of the following C++ programming topics:
- C++ Functions
- C++ if, if...else and Nested if...else
- C++ Recursion
- C++ User-defined Functions
- C++ while and do/while Loop
Example 1: Program to Convert Octal Number to Decimal
#include <iostream>
#include <cmath>
using namespace std;
int octalToDecimal(int octalNumber);
int main()
{
int octalNumber;
cout << "Enter an octal number: ";
cin >> octalNumber;
cout << octalNumber << " in octal = " << octalToDecimal(octalNumber)
<< " in decimal";
return 0;
}
// Function to convert octal number to decimal
int octalToDecimal(int octalNumber)
{
int decimalNumber = 0, i = 0, rem;
while (octalNumber != 0)
{
rem = octalNumber % 10;
octalNumber /= 10;
decimalNumber += rem * pow(8, i);
++i;
}
return decimalNumber;
}Output 1
Enter an octal number: 2341 2341 in octal = 1249 in decimal
Working
In the program, the octal number is stored in the variable octalNumber and passed to function octalToDecimal().
This function converts the octal number passed by user to its equivalent decimal number and returns it to main() function.
Example 2: Program to Convert decimal number to octal
#include <iostream>
#include <cmath>
using namespace std;
int decimalToOctal(int decimalNumber);
int main()
{
int decimalNumber;
cout << "Enter a decimal number: ";
cin >> decimalNumber;
cout << decimalNumber << " in decimal = "
<< decimalToOctal(decimalNumber) << " in octal";
return 0;
}
// Function to convert decimal number to octal
int decimalToOctal(int decimalNumber)
{
int rem, i = 1, octalNumber = 0;
while (decimalNumber != 0)
{
rem = decimalNumber % 8;
decimalNumber /= 8;
octalNumber += rem * i;
i *= 10;
}
return octalNumber;
}Output 1
Enter an decimal number: 78 78 in decimal = 116 in octal
Working
In the program, the decimal number is stored in the variable decimalNumber and passed to function decimalToOctal().
This function converts the decimal number passed by user to its equivalent octal number and returns it to main() function.
Next Example
We hope that this Example helped you develop better understanding of the concept of "Convert Octal Number to Decimal and vice-versa" in C++.
Keep Learning : )
In the next Example, we will learn about C++ Convert Binary Number to Octal and vice-versa.