Loop Exercises
Write a C program to input Octal number from user and convert to Decimal number system. How to convert from Octal number system to Decimal number system in C program. Logic to convert octal to decimal number system in C programming.
Required knowledge
Basic C programming, While loop
Octal number system
Octal number system is a base 8 number system. Octal number system uses 8 symbols to represent all its numbers i.e. 01234567
Decimal number system
Decimal number system is a base 10 number system. Decimal number system uses 10 symbols to represent all its numbers i.e. 0123456789
Logic to convert from octal to decimal
Algorithm Conversion Octal to Binary
begin: read(octal); decimal ? 0; rem ? 0; place ? 0; While(octal !=0) begin: rem ? octal % 10; decimal ? decimal + (8place * rem); octal ? octal / 10; place ? place + 1; end; write('Decimal =' decimal); end;
Program to convert octal to decimal number system
/** * C program to convert Octal number system to Decimal number system */ #include <stdio.h> #include <math.h> int main() { long long octal, tempOctal, decimal; int rem, place; /* Input octal number from user */ printf("Enter any octal number: "); scanf("%lld", &octal); tempOctal = octal; decimal = 0; place = 0; /* * Convert octal to decimal */ while(tempOctal > 0) { /* Extract the last digit of octal */ rem = tempOctal % 10; /* Convert last octal digit to decimal */ decimal += pow(8, place) * rem; /* Remove the last octal digit */ tempOctal /= 10; place++; } printf("Octal number = %lld\n", octal); printf("Decimal number = %lld", decimal); return 0; }
Output
Enter any octal number: 172
Octal number = 172
Decimal number = 122