Question

Is it possible to have a function that takes (int n,bool wantall) and returns a different type based on the bool?
The example that made me think about this was generate the fibonacci numbers.
If wantall = true, then return an array (or list) of the first n numbers, else, just return the nth number.
Is there a way to do this?

Answer 1

No, you can’t change the return type.

For your example, ideally you should have different overloads for what you are talking about

GetFirstFibonacciNumbers(int count)
GetSingleFibonacciNumber(int nth)

Passing in a bool for this is just ugly.

But if you insist on a single method

IEnumerable<int> GetFibonacciNumbers(int n, bool wantall) {
    if(!wantall) {
        return new[] { GetSingleFibonacciNumber(n); }
    }
    else {
        return GetFirstFibonacciNumbers(n);
    }
}

But, please, don’t do this.