Array of dictionaries in C#

Question

I would like to use something like this:

Dictionary[] matrix = new Dictionary[2];

But, when I do:

Answer 1

You forgot to initialize the Dictionary. Just put the line below before adding the item:

matrix[0] = new Dictionary<int, string>();

Answer 2

Try this:

Dictionary<int, string>[] matrix = new Dictionary<int, string>[] 
{
    new Dictionary<int, string>(),
    new Dictionary<int, string>()
};

You need to instantiate the dictionaries inside the array before you can use them.

Answer 3

Dictionary<int, string>[] matrix = new Dictionary<int, string>[2];

Doing this allocates the array 'matrix', but the the dictionaries supposed to be contained in that array are never instantiated. You have to create a Dictionary object in all cells in the array by using the new keyword.

matrix[0] = new Dictionary<int, string>();
matrix[0].Add(0, "first str");

Answer 4

You've initialized the array, but not the dictionary. You need to initialize matrix[0] (though that should cause a null reference exception).

Answer 5

Did you set the array objects to instances of Dictionary?

Dictionary<int, string>[] matrix = new Dictionary<int, string>[2];
matrix[0] = new Dictionary<int, string>();
matrix[1] = new Dictionary<int, string>();
matrix[0].Add(0, "first str");