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Hi all,
I have an application in which i get the id's from a gridview and save it in an integer list List<int>.

C#
```List<int> list = new List<int>();

//Example say, if the values in my list is

list={100,100,101,124,155,114,101};

//I want my list to return only unique values as i am passing my list to a database for retrieving data.

//I want my list to return like this.

list={100,101,124,155,114};```

How can i do this.Pls help me....
Posted
Updated 14-Apr-21 8:54am

## Solution 4

Check this

XML
```List<int> list = new List<int>();
list = list.Distinct().ToList();```

Now this will have 100 and 101

ajithk444 10-Oct-12 7:28am
thank U.:)it helped:)

## Solution 3

Why not using LINQ ?

C#
```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```

v2
TheCoolCoder 10-Oct-12 6:12am
Was abt to post this and thought about refreshing :-)..
Andy411 10-Oct-12 6:18am
:-)
ajithk444 10-Oct-12 7:28am
thank U.:)it helped:)

## Solution 1

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

C#
`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.

ajithk444 10-Oct-12 7:28am
thank U.:)it helped:)
MT_ 10-Oct-12 8:42am

## Solution 2

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 `Find`command 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[^]

v3
ajithk444 10-Oct-12 7:28am
thank U.:)it helped:)
Nelek 11-Oct-12 7:06am
You are welcome. :)

## Solution 5

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

C#
```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)
{
}
}

IEnumerable<int> distinctlist = list.Distinct();
foreach (int id in distinctlist)
{
}
return Newlist;```

v3
MT_ 10-Oct-12 8:43am
You can replace IEnumerable<int> distinctlist = list.Distinct(); by newList = IEnumerable<int> distinctlist = list.Distinct().ToList();
MT_ 10-Oct-12 8:43am
That will save you a foreach loop.