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Question

Split a List of structs into sublists based on the stucts contents

Answer 1

+2 A:

List<List<StructType>> groupings = list.GroupBy(x => x.GroupingString)
                                       .Select(x => x.ToList()).ToList();

Mehrdad Afshari 2010-02-25 16:31:29

ouch!!!!!!!!!!!!!! :)

leppie 2010-02-25 16:31:55

@leppie: why? Isn't this what the OP says he wants? :-?

Mehrdad Afshari 2010-02-25 16:33:04

I'd probably skip the entire second line (keep it as an IEnumerable of IGroupings), but this IS specifically what he asked for. :)

Sapph 2010-02-25 16:36:24

@Mehrdad Afshari: It is correct, but `ToLookup` just does it so much nicer :) OTOH, yours will generate more efficient Linq2SQL. :)

leppie 2010-02-25 16:43:03

Answer 2

+2 A:

somelist.ToLookup(x => x.GroupingString)

leppie 2010-02-25 16:31:30

How do I get a List/Array's out of the Grouping that generates?

Dan Neely 2010-02-25 16:55:23

@Dan Neely: You can either iterate and use the `Key` property, or do a direct lookup using the indexer (think it uses a backing Dictionary). If you dont need the key, I would probably go with Mehrdad Afshari suggestion.

leppie 2010-02-25 17:00:27

Am I missing something? This crashes when I try to iterate the results and cast them back into a list:foreach (List<MyStruct> foo in someList.ToLookup(x => x.ident))

Dan Neely 2010-02-25 17:10:11

@Dan Neely: `IEnumerable<MyStruct>`

leppie 2010-02-25 17:31:54

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Split a List of structs into sublists based on the stucts contents

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