Question

I m in a situation where i need to find record from a generic list using its position, means need to find 1st 5th and 9th record , then 2nd 6th and 10th record and so on…

Situation is

A list of projects assigned to a List of Team,
So if we have 20 projects and 4 teams

then 1st project go to 1st team, 2nd go to 2nd team , 3rd go to 3rd team, 4th go to 4th team
then again 5th project go to 1st team

so its like

Projects              Team
1                     1
2                     2
3                     3
4                     4
5                     1
6                     2
7                     3
8                     4
9                     1
.
.

so now i want to run a Query on Generic List to get record for each team, so for first team record 1,5 and 9…. need to fetch.

Some thing like

 List<Project> lst = list (from Database)
 //For 1stTeam 
lst = lst.Index(1,5,9...);

//For 2nsTeam 
lst = lst.Index(2,6,10...);

Hope i clear my point.

Answer 1

First, this is not specific to generic lists.

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You have to create a new list, and then, one by one, add the items from the original list that you want in the new list. You can access single items at a given position via the indexer (square brackets).

List<Project> lst = // list (from Database)

List<Project> firstTeam = new List<Project>();
firstTeam.Add(lst[1]);
firstTeam.Add(lst[5]);
firstTeam.Add(lst[9]);

List<Project> secondTeam = new List<Project>();
secondTeam.Add(lst[2]);
secondTeam.Add(lst[6]);
secondTeam.Add(lst[10]);

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Of course, if the items are distributed that regularly throughout the original lst, you can automatically determine the items:

List<Project> firstTeam = new List<Project>();
for (int i = 1; i < lst.Count; i += 4) {
    firstTeam.Add(lst[i]);
}

i.e. you loop over the original list, taking every 4th item.

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If the items to add to one of the teams are not distributed regularly throughout lst, you will have to add them one by one, but you might be able to make use of the shorter list initializer syntax:

List<Project> firstTeam = new List<Project>() { lst[1], lst[5], lst[9] };

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Lastly, note that List<T> starts counting indices at zero, so the very first item is lst[0], not lst[1].