Data cannot be assigned

Question

Hello why in this function data could not be read(assigned)? Error is in the line with comments(Object reference not set to an instance of an object.)

protected static int[][] GetMapFromFile(ref int size)
    {         
        using (StreamReader sr = new StreamReader(@"C:\Users\doman\OneDrive\Desktop\Antras semestras\Programavimas\Laboras1\Laboras1\Duomenys.txt"))
        {
            string skyr = " ,.;";
            size = Convert.ToInt32(sr.ReadLine());
            int[][] map = new int[size][];
            for (int i = 0; i < size; i++)
            {
                string line = sr.ReadLine();
                string[] values = line.Split(skyr.ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
                for (int j = 0; j < values.Length; j++)
                {
                    map[i][j] = Convert.ToInt32(values[j]); // Error here
                    Console.Write(map[i][j]);
                }
                Console.WriteLine();
            }

            return map;
        }
    }

My data file
5
0 1 3 4 2
1 0 4 2 6
3 4 0 7 1
4 2 7 0 7
2 6 1 7 0

Answer 1

You need to create each "sub" array. Add map[i] = new int[values.Length] before the second for loop.