C# 2D array - input -> output problem

Question

Hello,

I have the following table.

Input 09.05.2022 --> Output 214
Input 09.08.2023 --> Output 344

What is the best way to detect this?
a) only code
b) read a file

Thanks for tips in advance.

200318-datetime-csv.txt

;1;2;3;4;5;6;7;8;9;10;11;12  
2022;237;238;239;240;241;242;243;244;245;246;247;248  
2023;337;338;339;340;341;342;343;344;345;346;347;348  
2024;437;438;439;440;441;442;443;444;445;446;447;448  

Answer 1

@Markus Freitag , you could try the following code to convert the file to a datatable and get the correspond value based on the input.

Code example:

 static void Main(string[] args)  
        {  
            List<List<string>> table = new List<List<string>>();  
  
            foreach (string line in System.IO.File.ReadLines("datetime-csv.txt"))  
            {  
                table.Add(line.Split(';').ToList());  
            }  
            DataTable table1 = new DataTable();  
            for (int i = 0; i < table[0].Count; i++)  
            {  
                table1.Columns.Add("Col"+i);  
            }  
            foreach (var item in table)  
            {  
                table1.Rows.Add(item.ToArray());  
            }  
  
            string ret = GetNewDateTime(DateTime.Now);  
            var year = Convert.ToInt32(ret.Substring(0, 4));  
            var month = Convert.ToInt32(ret.Substring(4));  
            string pattern = string.Format("Col0='{0}'", year);  
            DataRow[] result = table1.Select(pattern);  
            int rowindex = table1.Rows.IndexOf(result[0]);  
            string result1 = table[rowindex][month].ToString();  
            Console.WriteLine(result1);  
            
            Console.ReadLine();  
  
        }  
  
        static string GetNewDateTime(DateTime dt)  
        {  
            return dt.ToString("yyyyMM");  
        }  

You could get the result 241 and datatable:

Update for show it in a datagirdview:

  private void Form1_Load(object sender, EventArgs e)  
        {  
            List<List<string>> table = new List<List<string>>();  
  
            foreach (string line in System.IO.File.ReadLines("datetime-csv.txt"))  
            {  
                table.Add(line.Split(';').ToList());  
            }  
            DataTable table1 = new DataTable();  
            for (int i = 0; i < table[0].Count; i++)  
            {  
                table1.Columns.Add("Col" + i);  
            }  
            foreach (var item in table)  
            {  
                table1.Rows.Add(item.ToArray());  
            }  
            dataGridView1.DataSource= table1;  
        }  

Result:

Best Regards,
Jack

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Answer 2

Your posts are always very confusing... I think you are asking how to use an index to return a value from a multidimensional array. In my opinion the data has unnecessary header which I assume are months. Anyway, indexes are needed to find the data. I used an enum but there are other ways to do this. You just need to a way to map the indexes to the rows and columns.

    public enum Year
    {
        _2022 = 1,
        _2023 = 2,
        _2024 = 3
    }

    public enum Month
    {
        Jan = 1,
        Feb = 2,
        Mar = 3,
        Apr = 4,
        May = 5,
        Jun = 6,
        Jul = 7,
        Aug = 8,
        Sep = 9,
        Oct = 10,
        Nov = 11,
        Dec = 12
    }

    class Program
    {
        static async Task Main(string[] args)
        {
            List<List<string>> table = new List<List<string>>();

            foreach (string line in System.IO.File.ReadLines("datetime-csv.txt"))
            {
                table.Add(line.Split(";").ToList());
            }

            foreach(List<string> row in table)
            {
                foreach(string cell in row)
                {
                    Console.Write($"{cell}\t");
                }
                Console.Write("\r\n");
            }

            Console.WriteLine();
            string result = GetValueByYearAndMonth(Year._2022, Month.May, table);
            Console.WriteLine($"Value = {result}");

            Console.WriteLine();
            string result2 = GetValueByYearAndMonth2(DateTime.Now, table);
            Console.WriteLine($"Value = {result2}");
        }

        private static string GetValueByYearAndMonth(Year year, Month month, List<List<string>> data)
        {
            return data[(int)year][(int)month];
        }

        private static string GetValueByYearAndMonth2(DateTime dt, List<List<string>> data)
        {
            int row = dt.Year - 2021;
            int month = dt.Month;
            return data[row][month];
        }
    }

Output

        1       2       3       4       5       6       7       8       9       10      11      12
 2022   237     238     239     240     241     242     243     244     245     246     247     248
 2023   337     338     339     340     341     342     343     344     345     346     347     348
 2024   437     438     439     440     441     442     443     444     445     446     447     448

Value = 241

Value = 241