using recursion instead of loops

Interestingly I had a lot of problems with recursion early on.

Your question is pretty simple, though. Go straight to your simplest case, then think of it as one more than your simplest case and how to get to your simplest case.

Recursion requires that your function call itself, so you can think of it as a sort of "stacked iteration" if you like.

There is a really, REALLY cool book on things like strange loops and recursions, and I would recommend it highly: Gödel, Escher, Bach: An Eternal Golden Braid by Douglas R. Hofstadter.

Your main loop could be like this:

void printAsterix(int n)
{
    printRow(n);

    if(n > 1) printAsterix(n - 1);

    printRow(n);
}        

Basically, on "n == 5" it prints a row of 5, then calls itself with n == 4, then prints another row of 5. This would give you the nested appearance.

You can also use recursion in how "printRow(n)" works. I'd suggest starting with a loop in there, get it all working with that, then make a recursive version of printRow. printRow would have to know to put the newlines on the end, once it finishes up. With that you need to take a minute to think through the recursion line by line and work out what order things will actually happen in:

void printRow(int n)
{
    cout << "*";

    if(n > 1)
    {
        printRow(n - 1);
    }
    else
    {
        cout << "\n\n";
    }
}

In this case it would go through and print a * for each of n 5,4,3,2,1, but then it'll notice n is not greater than 1, so instead of calling itself again it will print the two newlines. You need to be careful with recursion artefacts such that the commands happen in the right order. For example if you wrote

void printRow(int n)
{
    if(n > 1)
    {
        printRow(n - 1);
    }
    else
    {
        cout << "\n\n";
    }

    cout << "*";
}

The stars are all being printed on the return-side of the recursive calls - this is, anything AFTER the recursion calls happen in the reverse order of things before the calls. This means the newlines would occur before the *'s. Which might be completely fine, but you need to account for it.