How to check a particular bit is SET or not using C program?

Learn: How to check whether a bit is SET (High) or not using C programming language? Here, we will read a number and bit and check input bit is SET or not.

Bitwise AND Operator (&) is used to check whether a bit is SET (HIGH) or not SET (LOW) in C and C++ programming language.

Bitwise AND Operator (&) is a binary operator, which operates on two operands and checks the bits, it returns 1, if both bits are SET (HIGH) else returns 0.

Let suppose, you want to check Nth bit of a Number NUM, you can do the same by following this syntax:

(NUM & (1<<N))

Here, NUM is the number whose bit you want to check and N is the bit number, (1<<N) SET the particular bit at N^th position.

Example: Statement (1<<3) returns 8 (in Binary: 0000 1000), see the binary 3^rd (count from 0 to 7) bit is SET here.

In this program:

Input:
Enter an 8 bits integer number: 31
Now, enter a bit number (from 0 to 7) to check, whether it is SET or not: 3
Output:
Bit number 3 is SET in number 31

Program to check whether bit is SET or not in C language

#include <stdio.h>

int main()
{
	int NUM; //to store number
	int N; //to store bit
	
	printf("Enter an 8 bits integer number: ");
	scanf("%d",&NUM);
	printf("Now, enter a bit number (from 0 to 7) to check, whether it is SET or not: ");
	scanf("%d",&N);

	//checking bit status
	if(NUM & (1<<N))
		printf("Bit number %d is SET in number %d.\n",N,NUM);
	else
		printf("Bit number %d is not SET in number %d.\n",N,NUM);
	
	return 0;	
}

Output

Enter an 8 bits integer number: 31
Now, enter a bit number (from 0 to 7) to check, whether it is SET or not: 3 
Bit number 3 is SET in number 31.

Here, the input was 31, which is 0001 1111 and its 3^rd bit is SET.

See the image: