Bit manipulation

Bit manipulation has four operations:

• set the bit
• clear the bit
• check the bit
• toggle the bit

Bit manipulation in C++

First we need to know the basic.

AND (&) Operation:

Binary result always comes in 0 or 1, It’s multiplication so 1&1 = 1 and other will come as zero.

OR (|) Operation:

Binary result always comes in 0 or 1, It’s addition so 0|0 = 0 and other will come as one.

XOR (^) Operation:

Binary result always comes in 0 or 1. (If both input are same then its zero)

 

Operation:

• set the bit: num = num | (1 << pos); //OR operator (0 | 1 = 1 , 1| 1 = 1)
• clear the bit: num = num & ~(1<< pos); // AND operator ( 0 & 0 = 0, 1 & 0 = 0)
• check the bit: bool ch = num & (1<<pos)?true:false;  //OR operator (0 & 1 =0, 1& 1 = 1)
• toggle the bit: num = num^(1<<pos);

Source code with example:

/*
Program: Bit Manipulation 
Author: Alpha Master
Date: 03 Nov 2021
*/

//Header File
#include<iostream>


int main()
{
	std::cout<<"Bit OPeration"<<std::endl;
	//its interger number and 4 byte, its each bit we can set
	//so we can use single integer to store 32 flags.
	int num = 0;
	int pos = 0;

	//setting
	//set the 5th bit
	//pos is starting from zero position
	pos  = 4;
	num = num | (1 << pos);
	//expected answer is 16 (10000)
	std::cout<<"value:"<<num<<std::endl;
	//set the 4th bit, expected answer is 11000 = 24
	pos = 3;
	num = num | (1 << pos);
	std::cout<<"value:"<<num<<std::endl;

    //set the 1st pos, expected answer is 11001 = 25
    pos = 0;
    num = num | (1 << pos);
    std::cout<<"value:"<<num<<std::endl;

	//clear
	pos = 0;
	num = num & ~(1<< pos);
	//expecting 24
	std::cout<<"value:"<<num<<std::endl;

	//check 5th bit
	pos = 4;
	bool ch = num & (1<<pos)?true:false;
	//expecting true
	std::cout<<"Status:"<<ch<<std::endl;
	pos = 2;
	ch = num & (1<<pos)?true:false;
	//expecting false
	std::cout<<"Status:"<<ch<<std::endl;

	//toggle
	num = num^(1<<pos);
    //expecting true
	ch = num & (1<<pos)?true:false;
    std::cout<<"Status:"<<ch<<std::endl;
	//toggle again
	num = num^(1<<pos);
    //expecting false
	ch = num & (1<<pos)?true:false;
    std::cout<<"Status:"<<ch<<std::endl;
		
    return 0;
}

Output:

Bit OPeration
value:16
value:24
value:25
value:24
Status:1
Status:0
Status:1
Status:0