How can I declare a two dimensional string array?

Question

string[][] Tablero = new string[3][3];

I need to have a 3x3 array arrangement to save information to. How do I declare this in C#?

Bernita

The documentation clearly shows how to do it: msdn.microsoft.com/en-us/library/9b9dty7d.aspx – Ropy

Also see c-how-to-initialize-an-array-of-2d-arrays – Sutherlan

Note that there is a difference between the OP code [][] (jagged array structure) and the accepted answer [,] (multidimensional), according to the link above. – Mortimer

Answer 1

string[,] Tablero = new string[3,3];

You can also instantiate it in the same line with array initializer syntax as follows:

string[,] Tablero = new string[3, 3] {{"a","b","c"},
                                      {"d","e","f"}, 
                                      {"g","h","i"} };

Arbuckle

Or var tablero = new string[3,3]; if you're using C# 3 or later – Prudential

If you use the array initializer syntax you don't need to provide the bounds (i.e. you can just write new string[,]) – Prudential

You don't need to write new string[,] at all ... string [,] Tablero = {{"a","b","c"}, {"d","e","f"}, {"g","h","i"} } – Tefillin

To clarify that first 3 in [3, 3] is the number of rows, the second 3 is the number of columns (everyone seems to have picked [3, 3] just to confuse :-)) – Hekking

Answer 2

You probably want this:

string[,] Tablero = new string[3,3];

This will create you a matrix-like array where all rows have the same length.

The array in your sample is a so-called jagged array, i.e. an array of arrays where the elements can be of different size. A jagged array would have to be created in a different way:

string[][] Tablero = new string[3][];
for (int i = 0; i < Tablero.GetLength(0); i++)
{
    Tablero[i] = new string[3];
}

You can also use initializers to fill the array elements with data:

string[,] Tablero = new string[,]
{
    {"1.1", "1.2", "1.3"},
    {"2.1", "2.2", "2.3"},
    {"3.1", "3.2", "3.3"}
};

And in case of a jagged array:

string[][] Tablero = new string[][]
{
    new string[] {"1.1", "1.2"},
    new string[] {"2.1", "2.2", "2.3", "2.4"},
    new string[] {"3.1", "3.2", "3.3"}
};

Backrest

Answer 3

You just declared a jagged array. Such kind of arrays can have different sizes for all dimensions. For example:

string[][] jaggedStrings =  {
new string[] {"x","y","z"},
new string[] {"x","y"},
new string[] {"x"}
};

In your case you need regular array. See answers above. More about jagged arrays

Carburetor

Answer 4

I assume you're looking for this:

        string[,] Tablero = new string[3,3];

The syntax for a jagged array is:

        string[][] Tablero = new string[3][];
        for (int ix = 0; ix < 3; ++ix) {
            Tablero[ix] = new string[3];
        }

Bontebok

Answer 5

There are 2 types of multidimensional arrays in C#, called Multidimensional and Jagged.

For multidimensional you can by:

string[,] multi = new string[3, 3];

For jagged array you have to write a bit more code:

string[][] jagged = new string[3][];
            for (int i = 0; i < jagged.Length; i++)
            {
                jagged[i] = new string[3];
            }

In short jagged array is both faster and has intuitive syntax. For more information see: this Stackoverflow question

Mortal

In the jagged case you can initialize it directly like string[][] jagged = { new[] { "a", "b", "c" }, new[] { "d", "e", "f" }, new[] { "g", "h", "i" } }; or var jagged = new[] { new[] { "a", "b", "c" }, new[] { "d", "e", "f" }, new[] { "g", "h", "i" } }; – Sutherlan

Answer 6

try this :

string[,] myArray = new string[3,3];

have a look on http://msdn.microsoft.com/en-us/library/2yd9wwz4.aspx

Kasi

This is a relevant article. The thing I can't stand about a lot of msdocs documentation is the use of just simple integers for examples. They should at least have a few other examples, especially one with strings. – Unterwalden

Answer 7

string[,] Tablero = new string[3,3];

Micaelamicah

Answer 8

When you are trying to create a multi-dimensional array all you need to do is add a comma to the declaration like so:

string[,] tablero = new string[3,3].

Ventris

Answer 9

string[][] is not a two-dimensional array, it's an array of arrays (a jagged array). That's something different.

To declare a two-dimensional array, use this syntax:

string[,] tablero = new string[3, 3];

If you really want a jagged array, you need to initialize it like this:

string[][] tablero = new string[][] { new string[3], 
                                      new string[3], 
                                      new string[3] };

Wittgenstein

Answer 10

A 3x3 (multidimensional) array can also be initialized (you have already declared it) like this:

string[,] Tablero =  {
                        { "a", "b", "c" },
                        { "d", "e", "f" }, 
                        { "g", "h", "i"} 
                     };

Sutherlan

-1: this is the same as https://mcmap.net/q/236620/-how-can-i-declare-a-two-dimensional-string-array and https://mcmap.net/q/236620/-how-can-i-declare-a-two-dimensional-string-array – Memorable

@JohnSaunders I fail to see. Leaving the entire type ignored on the rhs is something different. – Sutherlan

No, it's exactly the same. – Memorable

@JohnSaunders I was suggesting a different way to initialize. Not many know that she can omit the size and even type on rhs during array initialization. Of course it does the same. Since the question is more like "how do I declare/initialize", this is one way too. See this Eric's answer in which he separately mentions each technique. – Sutherlan

Oh, ok. I would get rid of my downvote, but it seems to have disappeared already. – Memorable

@JohnSaunders I was never downvoted though you claim to have made so :) may be network error.. – Sutherlan

Answer 11

you can also write the code below.

Array lbl_array = Array.CreateInstance(typeof(string), i, j);

where 'i' is the number of rows and 'j' is the number of columns. using the 'typeof(..)' method you can choose the type of your array i.e. int, string, double

Atrium

Answer 12

There are many examples on working with arrays in C# here.

I hope this helps.

Thanks, Damian

Armrest