How to iterate over a multidimensional string array?

Question

I have a 2d string array (at least I think it is called a 2d array):

var target = new string[var1,var2];

Now I want to convert it to List<List<string>> :

var listlist = new List<List<string>>();
foreach (var row in target)
{
  var newlist = new List<string>();
  foreach (var el in row)
  {
    newlist.Add(el);
  }
  listlist.Add(newlist);
}

But row has a type is string and el has type is char .

I can't understand why el is not a string ? What's wrong?

Answer 1

A foreach interates over a string[,] like it is a string[] . It doesn't split in rows.

If you do want to handle 'rows' and 'columns' those separately, you have to get the dimensions of the array, using the GetLength method:

var target = new string[var1, var2];

var listlist = new List<List<string>>();
for (int x = 0; x < target.GetLength(0); x++)
{
    var newlist = new List<string>();
    for (int y = 0; y < target.GetLength(1); y++)
    {
        newlist.Add(target[x, y]);
    }
    listlist.Add(newlist);
}

Answer 2

This is what you need

    static void SoStrList()
    {
        int var1=10, var2=7;
        var target=new string[var1, var2];

        var listlist=new List<List<string>>();

        for(int i=0; i<var1; i++)
        {
            var row=new List<string>();
            for(int j=0; j<var2; j++)
            {
                row.Add(target[i, j]);
            }
            listlist.Add(row);
        }
    }

Answer 3

use for loop instead of foreach

        var target = new string[2, 2];
        target[0, 0] = "a";
        target[0, 1] = "A";
        target[1, 0] = "b";
        target[1, 1] = "B";

        var listlist = new List<List<string>>();

        for (int i = 0; i < target.GetLength(0); i++)
        {
            var newlist = new List<string>();

            for (int j = 0; j < target.GetLength(1); j++)
                newlist.Add(target[i,j]);

            listlist.Add(newlist);
        }

Answer 4

Here:

foreach (var row in target)

You already have first element of your 2d array, and foreach take all chars of this elements

Answer 5

well ... string is array of chars. And this confusion is what you get from using keyword var for almost everything. Its not javascript.

Secondly : You need to go for something like this

for (int i = 0; i < target.GetLength(0); i++)
        {
            for (int y = 0; y < target.GetLength(1); y++)
            {
                your manipulation with strings
            }
        }

but srsly... get rid of vars !!!

Answer 6

For LINQ lovers, the same can be achieved using the following two lines:

int R = s.GetLength(0), C = s.GetLength(1);
var MyList = Enumerable.Range(0, R).Select(i => i * C).Select(i => s.Cast<string>.Skip(i).Take(C).ToList()).ToList();