## C Program to Convert Octal Number to Decimal Number

June 5, 2021 This program converts an octal number to an equivalent decimal number.

## Example: Program to Convert Octal to Decimal

In this program, we have created a user defined function for octal to decimal conversion. The program takes the octal number (entered by user) as input and converts it into a decimal number using function. To understand this program, you should have the knowledge of following C programming topics:

1. C – User defined functions
2. while loop in C
```#include <stdio.h>
#include <math.h>
/* This function converts the octal number "octalnum" to the
* decimal number and returns it.
*/
long octalToDecimal(int octalnum)
{
int decimalnum = 0, temp = 0;

while(octalnum != 0)
{
decimalnum = decimalnum + (octalnum%10) * pow(8,temp);
temp++;
octalnum = octalnum / 10;
}

return decimalnum;
}
int main()
{
int octalnum;

printf("Enter an octal number: ");
scanf("%d", &octalnum);

printf("Equivalent decimal number is: %ld", octalToDecimal(octalnum));

return 0;
}```

Output:

```Enter an octal number: 754
Equivalent decimal number is: 492```