how to reverse a string in c 2b 2b using while loop

1#include <iostream>
2using namespace std;
3
4int main() {
5 
6  string greeting = "Hello";
7  int len = greeting.length();
8  int n = len-1;
9  int i = 0;
10  while(i<=n){
11    //Using the swap method to switch values at each index
12    swap(greeting[i],greeting[n]);
13    n = n-1;
14    i = i+1;
15
16  }
17  cout<<greeting<<endl;
18}