Thread: reverse string using recursive

Code:

#include <iostream>
#include <string>
using namespace std;

void reverse(string, int);

int main()
{
    string s = "Example";
    
    cout << s<< endl;;
    
    reverse(s, 0);
} // end main

void reverse(string reverse, int i=0)
{
    if (start == reverse.length())
        return;
    
    reverse(reverse,i+1);
    cout << reverse[i];
}

I understand most of this code but only thing i don't understand is the last 2 line.

Code:

 reverse(reverse,i+1);
    cout << reverse[i];

how does the index goes to the end of the array when i is 0?

First this code will not compile because of errors. The first error is you are trying to use the same name for your variable and your function. Second start is not defined.

Code:

void reverse(string toReverse, int i=0)
{
    if (i == toRreverse.length())
        return;
     
    reverse(toReverse,i+1);
    cout << toReverse[i];
}

So after fixing those problems, what I think is confusing you is the following line:

Code:

void reverse(string toReverse, int i=0)

The int i=0 in the above is called a default argument, this function can be called with one or two arguments. If you call the function with one argument then it will use zero for the second argument. If you call the function with two arguments then the passed argument will be used instead of the zero. See this link for a more detailed description: Functions II.

Jim