Question

I have a question about deleting duplicates from array list. I want to join two strings from two tables and then split it. Compare the string from one table with others, if duplicates exist then delete it.
I did it with this code but i’m asking if there is another faster and shorter way to do it?

table1: String a = "abc"

table2: String b = "def,abc,okl"

Result: "abc,def,okl"

My code:

foreach(DataRow tr in transM.Rows)
{
    foreach(DataRow tb in tableDGV1.Rows)
    {
        if (tr["ID"].ToString() == tb["ID"].ToString())
        {
            string trMitter = tr["Tr"].ToString() + "," + tb["Tr"].ToString();
            string[] trSplit = trMitter.Split(new char[] {','}, StringSplitOptions.RemoveEmptyEntries);
            List<string> listTr = new List<string>(trSplit);

            for (int k = 0; k < listTr.Count; k++)
            {
                for (int g = k + 1; g < listTr.Count; g++)
                {
                    if (listTr[g].ToString() == listTr[k].ToString()) listTr.RemoveAt(g);
                }
            }
        }
    }
}

Answer 1

I you are using .Net V 3.5 or later, you can simply use

var firstSource = firstString.Split(','); 
var secondeSource = secondString.Split(',');
var result = firstSource.Union(secondSource);`

Or use .Distinct():

foreach(DataRow tr in transM.Rows)
{
    foreach(DataRow tb in tableDGV1.Rows)
    {
        if (tr["ID"].ToString() == tb["ID"].ToString())
        {
            string trMitter = tr["Tr"].ToString() + "," + tb["Tr"].ToString();
            string[] trSplit = trMitter.Split(new char[] {','}, StringSplitOptions.RemoveEmptyEntries);

            IEnumerable<string> noDuplicate = trSplit.Distinct();              

        }
    }
}

Or in more Linqish style :

var noDuplicate = from DataRow row1 in transM.Rows
                  from DataRow row2 in tableDGV1.Rows
                  where row1["ID"].Equals(row2["ID"])
                  let array1 = row1["tr"].ToString().Split(',', StringSplitOptions.RemoveEmptyEntries)
                  let array2 = row2["tr"].ToString().Split(',', StringSplitOptions.RemoveEmptyEntries)
                  select array1.Union(array2).Distinct();