CTechnotips: Octal to binary conversion in c language

Octal to binary conversion method:

To convert or change the octal number to binary number replace the each octal digits by a binary number using octal to binary chart.

Octal	Binary
0	000
1	001
2	010
3	011
4	100
5	101
6	110
7	111

Octal to binary table

Octal to binary conversion examples:

For example we want to convert or change octal number 65201 to decimal. For this we will replace each octal digit to binary values using the above table:

Octal number:   6   5   2   0   1

Binary values: 110 101 010 000 001

So (65201)₈ = (110101010000001)₂

C program to convert binary to octal

#include<stdio.h>

#define MAX 1000

int main(){

   

    char octalNumber[MAX];

    long int i=0;

    printf("Enter any octal number: ");

    scanf("%s",octalNumber);

    printf("Equivalent binary value: ");

    while(octalNumber[i]){

        switch(octalNumber[i]){

             case '0': printf("000"); break;

             case '1': printf("001"); break;

             case '2': printf("010"); break;

             case '3': printf("011"); break;

             case '4': printf("100"); break;

             case '5': printf("101"); break;

             case '6': printf("110"); break;

             case '7': printf("111"); break;

             default:  printf("\nInvalid octal digit %c ",octalNumber[i]); return 0;

    }

    i++;

 }

    return 0;

}

Sample output:

Enter any octal number: 123

Equivalent binary value: 001010011