Return Unique values from a List in C#

Why not using LINQ ?

List<int> l = new List<int>() { 100, 100, 101, 102, 103, 102 };

var v = l.Distinct();

foreach (var item in v)
{
    Debug.WriteLine(item.ToString());
}

// or

List<int> li = l.Distinct().ToList();

Will give you:

100
101
102
103

Either you can write your own algorithm or if you are using .Net 3.5 and above use HasSet.

Once you have your values in list, use following code

HashSet<int> uniqueNumbers = new HashSet<int>(list);</int></int>

This will give a HashSet with unique number, in your case list of 5 values only.

A possibility for your own function (as said in solution 1)

You can start copying the first element to the second list and then delete it with RemoveAt, then use the Findcommand with that element. If found... remove it and try to find it another time, If not found start from the beggining with the next item to be copied to the second list.

You can use the FindAll and RemoveAll as well

Have a look
http://msdn.microsoft.com/en-us/library/6sh2ey19.aspx[^]

THIS IS HOW I DID in a big complicated manner though.Anyway thanks for all ur feedback.It helped a lot.

public List<int> GetEmpID() //Get unique ID's in a list 
    {
        List<int> list = new List<int>();
        List<int> Newlist = new List<int>();
        foreach (GridViewRow gvr in this.gridBWAProject.Rows)
        {
            if (((System.Web.UI.WebControls.CheckBox)gvr.FindControl("chkSelect")).Checked == true)
            {
                list.Add(Convert.ToInt32(gvr.Cells[1].Text.ToString()));
            }
        }
        
        IEnumerable<int> distinctlist = list.Distinct();
        foreach (int id in distinctlist)
       {
        Newlist.Add(id);
       }
        return Newlist;