LINQ Map one type to another

Question

I need to find difference between to sets. Classes ,comprising the sets, are different but have same type of fields. To be able to use Except method ,to take the difference, i want to map one list to another.

Can i do this using toList method? if not, Is it possible in another way?

List<Class1>.Except(List<Class2> I need to map class2 list to class1 list)

Thanks

score 15 · Accepted Answer · answered Dec 26 '10 at 14:58

15

In LINQ, Select is synonymous with "map" in other languages. It is called "select" because the word comes from database terminology... but Select is what you want:

var mappedTypes = myCollection.Select(item => new MappedType(item.Something));

answered Dec 26 '10 at 14:58

Brian Genisio

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score 1 · Answer 2 · answered Dec 26 '10 at 14:52

1

If you want a projection you can use ye olde Select operator:

list1.Except(list2.Select(x => ConvertToClass1(x));

answered Dec 26 '10 at 14:52

R. Martinho Fernandes

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score 0 · Answer 3 · edited May 12 '21 at 19:54

0

List<Class1>.Except(List<Class2>.Select(e => 
                                           new Class1() 
                                                    { 
                                                      Field1 = e.Field1 ...
                                                    });

However, I would advise you to use automapper.

edited May 12 '21 at 19:54

mskfisher

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answered Dec 26 '10 at 14:53

Femaref

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LINQ Map one type to another

3 Answers3