Swapping of numbers without using third variable

 In this I will tell you how to do swapping of two numbers without using third variable in c. So , Without any further delay let's get started . In this we are going to use bitwise ^(XOR) operator . 

Let us first understand the working of XOR(^) operator .

                             Truth  Table

A                             B                                       A^B

0                              0                                         0

1                              0                                         1

0                              1                                         1

1                              1                                         0

Now you have seen how this operator going to work . Let's us see code .

Code:

#include <iostream>

using namespace std;

int main()

{

    int a = 5, b = 4;

    cout << "Before doing swapping :" << endl;

    cout << "a = " << a << " b = " << b << endl;

    a = a ^ b; // here the value of a become 1 after doing operation

    b = a ^ b; // here value of b become 5 after doing operation

    a = a ^ b; // here value of a become 4 after doing operation

    cout << "After doing swapping : " << endl;

    cout << "a = " << a << " b = " << b << endl;

    return 0;

}

Logic:

Let us understand what we are doing here . we have take two variable

a = 5 and b = 4 of type int . Then we print the values before swapping.

We all known that binary of 5 is 101 and 4 is 100 . When we first perform

XOR(^) on a and b it then value of a become in binary 001 i.e. 1.That is

easily understand by Truth table. Then we again perform this operation

now value of b become 5 (in binary 101) by doing XOR(^) of a and b .

Now we again do XOR(^) of a(is 001) and b(is 101) and value of a become 4(100).

Output:

Now we can see that our program work correctly. You can try this by

taking input from the console . And can check its accuracy . It is

better than traditional third variable. And it is perform on bits so

it is faster than that .

I hope this is helpful to you in your work.

Thanks for reading.