Why manipulate bits?

When working with embedded devices each bit of an integer can be important to keep track of. Specially when reading and writing to hardware registers sometimes simply flipping a single incorrectly set bit can be the solution to hours of unexpected bahaviour and troubleshooting.

Bitwise operators

int main()
{
	int a = 0x01;
	int b = 0x02;
	int c = 0x03;
    return 0;
}

Setting a bit

The following code sets the 3rd bit in integer n high.
Inititally When n is printed it will print 1 based on its declaration but the second time it will evaluate to a value of 9 after the bit manipulation.

int n = 0b00000001;
printf("$d\n", n);	// outputs 1

n |= (0b1) << 3;	// changed to 0b00001001
printf("$d\n", n);	// outputs 9

Clearing a bit

int main()
{
	int a = 0x01;
	int b = 0x02;
	int c = 0x03;
    return 0;
}

Bitmasking

using namespace std;

int main()
{
	int mask = 0x0FF;
    return 0;
}

Practice

To further test your understanding use the following leetcode challenges

• https://leetcode.com/explore/learn/card/bit-manipulation/
• https://leetcode.com/problem-list/bit-manipulation/