The following c# code splits the clientIds into smaller lists, each containing up to 100 elements.

var listOfClientIdLists = clientIds
    .Select((v, i) => new { Value = v, Index = i })
    .GroupBy(g => g.Index / 100, gi => gi.Value)
    .Select(chunk => chunk.ToList())
    .ToList();

### Explanation

1. Select((v, i) => new { Value = v, Index = i }):

- This uses the Select method with an overload that provides both the element (v) and its index (i).
- It transforms the clientIds collection into a new collection of anonymous objects, each containing:
- Value: the original element (v).
- Index: the position of the element in the original list (i).

2. GroupBy(g => g.Index / 100, gi => gi.Value):

- The GroupBy method organizes the elements into groups.
- g => g.Index / 100: This lambda expression determines the group key by dividing the index by 100. This effectively groups the elements into chunks of 100.
- gi => gi.Value: This specifies that only the Value part of the anonymous object should be included in the groups.

3. Select(chunk => chunk.ToList()):

- This converts each group (or chunk) into a list.

4. ToList():

- This final ToList converts the collection of lists into a list of lists.

### Alternative
Claude.AI suggests a better way to achieve the same goal, which has better simplicity and readability.

var listOfClientIdLists = clientIds
    .Chunk(100)
    .Select(chunk => chunk.ToList())
    .ToList();

#csharp #tips