C# loop over an array of unknown dimensions

Question

I want to create an extension method to loop over System.Array with unknown number of dimensions

For now I am using a naive approach:

public static void ForEach<T>(this Array source, Action<T> action)
{
    if(source.Rank == 1)
    {
        for (int w = 0; w < source.GetLength(0); w++)
        {
            action((T)source.GetValue(w));
        }
    }
    else if(source.Rank == 2)
    {
        for (int h = 0; h < source.GetLength(1); h++)
        {
            for (int w = 0; w < source.GetLength(0); w++)
            {
                action((T)source.GetValue(h, w));
            }
        }
    }
    else if(source.Rank == 3)
    {
        // etc
    }
}

I am sure, there is much more elegant way of doing that. But I can not figure it out. How do I generalize that method for unlimited number of dimensions ?

Answer 1

If you don't care about the indices, you can just iterate over a System.Array with absolutely no knowledge of its Rank. The enumerator will hit every element.

public class Program
{
    public static void IterateOverArray(System.Array a)
    {
        foreach (var i in a)
        {
            Console.WriteLine(i);
        }
    }

    public static void Main()
    {
        var tests = new System.Array []
        {
            new int[] {1,2,3,4,5,6,7,8},
            new int[,]
            {
                {1,2},{3,4},{5,6},{7,8}
            },
            new int[,,]
            {
                {  {1,2},{3,4} },
                {  {5,6},{7,8} }
            }
        };


        foreach (var t in tests)
        {
            Console.WriteLine("Dumping array with rank {0} to console.", t.Rank);
            IterateOverArray(t);
        }
    }
}

Output:

Dumping array with rank 1 to console.
1
2
3
4
5
6
7
8
Dumping array with rank 2 to console.
1
2
3
4
5
6
7
8
Dumping array with rank 3 to console.
1
2
3
4
5
6
7
8

Link to DotNetFiddle example