# C program to clear nth bit of a number

Write a C program to input any number from user and clear the nth bit of the given number using bitwise operator. How to clear nth bit of a given number using bitwise operator in C programming. How to unset (0) the value of nth bit of a given number in C.

Example

Input

```Input number: 13
Input nth bit to clear: 0
```

Output

```Number after clearing nth bit: 12 (in decimal)
```

## Logic to clear nth bit of a number

To clear nth bit of a number we will use combination of bitwise left shift `<<`, bitwise complement `~` and bitwise AND `&` operator.

Below is the step by step descriptive logic to clear nth bit of a number.

1. Input number and nth bit position to clear from user. Store it in some variable say num and n.
2. Left shift 1, n times i.e. `1 << n`.
3. Perform bitwise complement with the above result. So that the nth bit becomes unset and rest of bit becomes set i.e. `~ (1 << n)`.
4. Finally, perform bitwise AND operation with the above result and num. The above three steps together can be written as `num & (~ (1 << n));`

Let us take an example to understand this. ## Program to clear nth bit of a number

``````/**
* C program to clear the nth bit of a number
*/

#include <stdio.h>

int main()
{
int num, n, newNum;

/* Input number from user */
printf("Enter any number: ");
scanf("%d", &num);

/* Input bit number you want to clear */
printf("Enter nth bit to clear (0-31): ");
scanf("%d", &n);

/*
* Left shifts 1 to n times
* Perform complement of above
* finally perform bitwise AND with num and result of above
*/
newNum = num & (~(1 << n));

printf("Bit cleared successfully.\n\n");
printf("Number before clearing %d bit: %d (in decimal)\n", n, num);
printf("Number after clearing %d bit: %d (in decimal)\n", n, newNum);

return 0;
}``````

Output

```Enter any number: 13
Enter nth bit to clear (0-31): 0
Bit cleared successfully.

Number before clearing 0 bit: 13 (in decimal)
Number after clearing 0 bit: 12 (in decimal)```

Happy coding 😉 