C# Return Different Types?

Question

I got something like this:

public [What Here?] GetAnything()
{
     Hello hello = new Hello();
     Computer computer = new Computer();
     Radio radio = ne         


        

Answer 1

It's a sample using Generic Types.

public T GetAnything() where T : class, new()
    => new T();

And you'll use this method calling this way:

var hello = GetAnything();

In this case, you can use an interface to specify a type to pass as parameter.

public T GetAnything() where T : ISomeInterface, new()
    => new T();

You must have a parameterless construtor in each class to use new() constraint.

Follow the full sample:

internal sealed class Program
{
    private static void Main(string[] args)
    {
        GetAnything().Play();
        GetAnything().Play();
        GetAnything().Play();
    }

    private static T GetAnything() where T : ISomeInterface, new()
        => new T();
}

internal interface ISomeInterface
{
    void Play();
}

internal sealed class Hello : ISomeInterface
{
    // parameterless constructor.
    public Hello() { }
    public void Play() => Console.WriteLine("Saying hello!");
}

internal sealed class Radio : ISomeInterface
{
    // parameterless constructor.
    public Radio() { }
    public void Play() => Console.WriteLine("Playing radio!");
}

internal sealed class Computer : ISomeInterface
{
    // parameterless constructor.
    public Computer() { }
    public void Play() => Console.WriteLine("Playing from computer!");
}