C Program to Convert Binary to Decimal

C programs to convert decimal to binary have been shown here.

Page content(s):

1. Program & output: Iterative approach

2. Program & output: Recursive approach

1. C Program to convert binary to decimal

Code has been copied

/*************************************
    	alphabetacoder.com
C program to convert binary to decimal
**************************************/

#include <stdio.h>
#include <math.h>

int main() {
    // declare variables
    long bin, num = 0;
    int r, i = 0;

    // take input
    printf("Enter the number in binary: ");
    scanf("%ld", & bin);

    // convert the number in decimal
    while (bin > 0) {
        r = bin % 10;
        num = num + r * pow(2, i);
        bin = bin / 10;
        i++;
    }

    // display the number in decimal
    printf("Decimal: %ld\n", num);

    return 0;
}

Output

Case 1:

Enter the number in binary: 1110

Decimal: 14

Case 2:

Enter the number in binary: 111111

Decimal: 63

2. C Program to convert binary to decimal using recursion

Code has been copied

/****************************
    alphabetacoder.com
C program to convert binary
to decimal using recursion
*****************************/

#include <stdio.h>

// function to display  
// binary to decimal
int binary_to_decimal(long bin) {
    if (bin == 0)
        return 0;
    else
        return (bin % 10 + 2 * binary_to_decimal(bin / 10));
}

int main() {
    // declare variables
    long bin;

    // take input
    printf("Enter the number in binary: ");
    scanf("%ld", & bin);

    // call function to display 
    // the binary to decimal
    printf("Decimal: %ld\n", binary_to_decimal(bin));

    return 0;
}

Output

Case 1:

Enter the number in binary: 1110

Decimal: 14

Case 2:

Enter the number in binary: 111111

Decimal: 63