C program to clear nth bit of a number

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

Example:
Input number: 13
Input nth bit to clear: 0
Output number after clearing nth bit: 12 (in decimal)

Required knowledge:

Basic C programming, Bitwise operator

Logic:

In previous two post I have already explained how to get and set n^th bit of any number. Here to clear n^th bit of a number we will use bitwise left shift <<, bitwise complement ~ and bitwise AND & operator. What we need to do is:

1. Left shift << 1(in decimal) to n times (where n is the bit number to be cleared).
2. Perform bitwise complement ~ operation with the above result so that the n^th bit becomes unset and rest of bit becomes set.
3. Now perform bitwise AND & operation with the above result and the number to get all set bits except the n^th bit.

Or in general perform number & (~(1 << n)) to clear the n^th bit.

Program:

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

#include <stdio.h>

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

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

    //Reads the 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
     * then perform bitwise AND with number 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;
} 

Happy coding ;)