Is it possible to extend arrays in C#?

Question

I'm used to add methods to external classes like IEnumerable. But can we extend Arrays in C#?

I am planning to add a method to arrays that converts it to a IEnumerable even if it is multidimensional.

Not related to How to extend arrays in C#

Solution 1

static class Extension
{
    public static string Extend(this Array array)
    {
        return "Yes, you can";
    }
}

class Program
{

    static void Main(string[] args)
    {
        int[,,,] multiDimArray = new int[10,10,10,10];
        Console.WriteLine(multiDimArray.Extend());
    }
}

Solution 2

Yes. Either through extending the Array class as already shown, or by extending a specific kind of array or even a generic array:

public static void Extension(this string[] array)
{
  // Do stuff
}

// or:

public static void Extension<T>(this T[] array)
{
  // Do stuff
}

The last one is not exactly equivalent to extending Array, as it wouldn't work for a multi-dimensional array, so it's a little more constrained, which could be useful, I suppose.

Solution 3

I did it!

public static class ArrayExtensions
{
    public static IEnumerable<T> ToEnumerable<T>(this Array target)
    {
        foreach (var item in target)
            yield return (T)item;
    }
}

Comments

[Alex Essilfie]

+1 Your implementation is more type-safe than @maciejkow's. I wrote some array extension methods using a similar method some time ago.

[VatsalSura]

What does "this Array array" mean in the method. I think Array is an abstract class so what are you exactly doing here by writing "this Array array"?

[VatsalSura]

What does "this Array target" mean in the method. I think Array is an abstract class so what are you exactly doing here by writing "this Array target"?

[SimonC]

this Array array means that this Array is referring to the type that is to be extended. this Array could just as well be this T, where the method would be public static void Extend<T>(this T obj). The identifier merely gives the type a name, so it can be referenced in the extending method.