Question

I would like to add arrays to a list or multidimensional array (not all at once…). But I dont really understand why this should be that hard.

Lets say I have this:

    string[] a = { "h", "b"};
    string[] b = { "c", "a", "i" };
    string[] c = { "out", "in", "file", "test" };

    ArrayList x = null;

    x.Add(a); //error: Object reference not set to an instance of an object.
    x.Add(b);
    x.Add(c);

Can I use instead of the ArrayList maybe

string[,] x = null;

But there is no option to .Add

Lets say I have an unknown amount of string[]´s with an unknown size – how do I add them to a List/multidimensional array? And again: I would like to add these string[]´s one by one. Any ideas?

Answer 1

You are getting an NullReferenceException because your list is not initialized:

string[] a = { "h", "b"};
string[] b = { "c", "a", "i" };
string[] c = { "out", "in", "file", "test" };

IList<string[]> x = new List<string[]>;

x.Add(a);
x.Add(b);
x.Add(c);

This assumes that you are constructing a 2-D structure. If you would like to “flatten” your arrays into a single list of strings, create a list, and use its List.AddRange method instead.