C Program to Convert Binary Number to Octal Number System

  • Write a C program to convert binary number to octal number system
  • Wap in C to convert a base 2 number to a base 8 number.

Required Knowledge

This program converts a binary number( base 2) to octal number (base 8). Binary number system is a base 2 number system using digits 0 and 1 whereas Octal number system is base 8 and using digits from 0 to 7. Given a binary number as input from user convert it to octal number.

For Example
0000011 in Binary is equivalent to 3 in Octal number system.

Algorithm to convert Binary to Octal number
  • Divide the input binary number in set of three binary digits, starting from least significant digit to most significant digit.
  • For every group of three digits, write the equivalent octal digit.

For Example:
Let Binary number is 11001100
Divide binary number in group of three from right side: (11)(001)(100)
Replace each group with equivalent octal digit : 314

C program to convert a decimal number to octal number

#include <stdio.h>  
  
int main() {
    /*Define an array of octal digits to binary */ 
    int octalDigitToBinary[8] = {0, 1, 10, 11, 100, 101, 110, 111};  
  
    long binaryNumber, octalNumber = 0, binaryCopy;  
    int threeDigits, multiple, counter;  

    multiple = 1;  
      
    /* 
     * Take a binary number as input from user 
     */  
    printf("Enter a Binary Number\n");  
    scanf("%ld", &binaryNumber);  
      
    /* 
     * Convert binary to octal number equivalent  
     */   
    while(binaryNumber != 0) {  
        threeDigits = binaryNumber % 1000;
        /*Search through octalDigitToBinary array */
        for(counter = 0; counter < 8; counter++) {  
            if(octalDigitToBinary[counter] == threeDigits) {  
                octalNumber = (counter * multiple) + octalNumber;  
                break;  
            }  
        }  
        /* Remove last three digits */
        binaryNumber = binaryNumber/1000;  
        multiple *= 10;  
    }  
    printf("Octal Mumber : %ld", octalNumber);  
  
    return 0;  
}
Output
Enter a Binary Number
11001100
Octal Mumber : 314
Enter a Binary Number
0000011
Octal Mumber : 3

Related Topics
C program to convert a binary number to hexadecimal number system
C program to convert octal number to binary number system
C program to convert a octal number to decimal number system
C program to convert octal number to hexadecimal number system
C program to multiply two numbers without using arithmetic operators
C program to convert temperature from celsius to fahrenheit
C program to convert binary number to decimal number system
C program to convert number of days to week, months and years
C program to make a simple calculator using switch statement
List of all C programs