Is it possible for a function to return two values?

Question

Is it possible for a function to return two values? Array is possible if the two values are both the same type, but how do you return two different type values?

Answer 1

Can a function return 2 separate values? No, a function in C# can only return a single value.

It is possible though to use other concepts to return 2 values. The first that comes to mind is using a wrapping type such as a Tuple<T1,T2>.

Tuple<int,string> GetValues() {
  return Tuple.Create(42,"foo");
}

The Tuple<T1,T2> type is only available in 4.0 and higher. If you are using an earlier version of the framework you can either create your own type or use KeyValuePair<TKey,TValue>.

KeyValuePair<int,string> GetValues() {
  return new KeyValuePair<int,sting>(42,"foo");
}

Another method is to use an out parameter (I would highly recomend the tuple approach though).

int GetValues(out string param1) {
  param1 = "foo";
  return 42;
}

Answer 2

In a word, no.

But you can define a struct (or class, for that matter) for this:

struct TwoParameters {
    public double Parameter1 { get; private set; }
    public double Parameter2 { get; private set; }

    public TwoParameters(double param1, double param2) {
        Parameter1 = param1;
        Parameter2 = param2;
    }
}

This of course is way too specific to a single problem. A more flexible approach would be to define a generic struct like Tuple<T1, T2> (as JaredPar suggested):

struct Tuple<T1, T2> {
    public T1 Property1 { get; private set; }
    public T2 Property2 { get; private set; }

    public Tuple(T1 prop1, T2 prop2) {
        Property1 = prop1;
        Property2 = prop2;
    }
}

(Note that something very much like the above is actually a part of .NET in 4.0 and higher, apparently.)

Then you might have some method that looks like this:

public Tuple<double, int> GetPriceAndVolume() {
    double price;
    int volume;

    // calculate price and volume

    return new Tuple<double, int>(price, volume);
}

And code like this:

var priceAndVolume = GetPriceAndVolume();
double price = priceAndVolume.Property1;
int volume = priceAndVolume.Property2;