Hexadecimal to Binary in C

What is hexadecimal?

The hexadecimal is a positional system that represents the numbers in sixteen distinct symbols by using 16 as a base. These distinct symbols, i.e., "0-9" represents the values from zero to nine, and "A-F" represents the values from ten to fifteen.

What is Binary?

The binary is a number which is represented with a base 2 numeral system, and it uses two symbols, i.e., 0 and 1.

Examples

Suppose the hexadecimal number is A12C. Now we calculate the binary value of the hexadecimal number.

Hexadecimal number=A12C

Binary value equivalent to A is 1010

Binary value equivalent to 1 is 0001

Binary value equivalent to 2 is 0010

Binary value equivalent to C is 1100

Therefore, the binary value equivalent to A12C is 1010000100101100.

Note: To convert hexadecimal into a binary number, the binary value of each digit of a hexadecimal number is evaluated and combined to get the binary number of a given hexadecimal number.

Let's understand through an example.

#include<stdio.h>
void hextobin(char b[]);
void main()
{
    char hex[]="A12C";
    hextobin(hex);
}
void hextobin(char hex[])
{
   int i=0; 
   while(hex[i])
   {
       switch(hex[i])
       {
           case '0':
           printf("0000");
           break;
           case '1':
           printf("0001");
           break;
           case '2':
           printf("0010");
           break;
           case '3':
           printf("0011");
           break;
           case '4':
           printf("0100");
           break;
           case '5':
           printf("0101");
           break;
           case '6':
           printf("0110");
           break;
           case '7':
           printf("0111");
           break;
           case '8':
           printf("1000");
           break;
           case '9':
           printf("1000");
           break;
           case 'A':
           printf("1010");
           break;
           case 'a':
           printf("1010");
           break;
           case 'B':
           printf("1011");
           break;
           case 'b':
           printf("1011");
           break;
           case 'C':
           printf("1100");
           break;
           case 'c':
           printf("1100");
           break;
           case 'D':
           printf("1101");
           break;
           case 'd':
           printf("1101");
           break;
           case 'E':
           printf("1110");
           break;
           case 'e':
           printf("1110");
           break;
           case 'F':
           printf("1111");
           break;
           case 'f':
           printf("1111");
           break;
       }
       i++;
   }}

In the above code, we want to calculate the binary value of "A12C". We first store this value in a character array named as hex[], and then we pass this array to a hextobin() function. The hextobin() will calculate the binary value of the number, it iterates over each element of an array through a while loop, and finds the binary value of each corresponding element through a switch statement.

Output