How does this swap function work in C++?

[needOfHelpCMath]

I can't understand how this code was able to swap or get this output:

	Based off of the following code what is the output of the main function?
void Swap(int& x, int y){				
	int temp = x;				
	x = y;						
	y = temp;					
	return;						
}						
				
int main(){

int a =12;
int b = 3;

Swap( b, a);
cout << a << “ “ << b << endl;return 0;
}

output : 12 12

 

[BAdhi]

Well if you look at the swap method signature, there is 'int & x' which means it takes the reference of the variable that's passed to the method, while 'int y' will only take the value of the variable that is passed to the method.

So since b is passes to the x in the swap function, what ever you do to x inside the function will actually affect the variable b.

But since only the value of a is passed to y, even if you changed the value of y nothing will happen to the value of a.

But since this is a swap function and actual requirement is to swap the values of a and b you should change the method signature from

void swap(int & x, int y)

to

void swap(int & x, int & y)