retrieving data into a 2D array in C#

Question

I have a text file that has:

1 2 3 4 0 5 6 7 8

How do I show the data in a 2D array of size [3,3]?

I'm new to C# and any help would be great!

I've tried the code below but it doesn't work:

int i = 0, j = 0;
int[,] result = new int[3, 3];
foreach (var row in input.Split('\n'))
{
    j = 0;
    foreach (var col in row.Trim().Split(' '))
    {
        result[i, j] = int.Parse(col.Trim());
        j++;
    }
    i++;
}

Console.WriteLine(result);

You might want to pass StringSplitOptions.RemoveEmptyEntries as a second parameter to Split() method. — Cosmin Sontu
– Cosmin Sontu, Commented Nov 30, 2019 at 17:15
In your example it looks like the file contains 9 numbers in one single row, but your code assumes the file to contains 3 rows with three numbers each. — Olivier Jacot-Descombes
– Olivier Jacot-Descombes, Commented Nov 30, 2019 at 17:22

Miq · Accepted Answer · 2019-11-30 17:27:30Z

2

divide by 3 and convert to integer to get row, use modulo 3 to get col.

 j=0;
 foreach (var col in input.Trim().Split(' '))
    {
        result[j/3, j%3] = int.Parse(col.Trim());
        j++;
    }

answered Nov 30, 2019 at 17:27

Miq

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Comments

kajacx · Accepted Answer · 2019-11-30 17:27:19Z

1

If all your 9 numbers are on the same line, then splitting by new line will not help. You can do:

foreach (var num in input.Split(' '))
{
    result[i / 3, i % 3] = int.Parse(num.Trim());
    i++;
}

because:

i    i / 3 (div)    i % 3 (mod)
0    0              0
1    0              1
2    0              2
3    1              0
4    1              1
5    1              2
6    2              0
7    2              1
8    2              2

answered Nov 30, 2019 at 17:27

kajacx

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