reference variablesr in c 2b 2b

1Value of i : 5
2Value of i reference : 5
3Value of d : 11.7
4Value of d reference : 11.7
5

1#include <iostream>
2 
3using namespace std;
4 
5int main () {
6   // declare simple variables
7   int    i;
8   double d;
9 
10   // declare reference variables
11   int&    r = i;
12   double& s = d;
13   
14   i = 5;
15   cout << "Value of i : " << i << endl;
16   cout << "Value of i reference : " << r  << endl;
17 
18   d = 11.7;
19   cout << "Value of d : " << d << endl;
20   cout << "Value of d reference : " << s  << endl;
21   
22   return 0;
23}