Finding items of a list that are not in the other list

Question

My object is like

class MyObject
{
string FirstName, string LastName, string Phone
}

and I have two list of this object:

incomingList<MyObject>
fullList<MyObject>

How can I have a list of the things that are in the incomingList but are not in the fullList

possible duplicate of [LINQ - compare two lists](http://stackoverflow.com/questions/9524681/linq-compare-two-lists) — cadrell0, Jul 24 '14 at 15:17
@cadrell0 Nop! that is a normal int type, mine is a custom type. They are different. — CutHimSomeSlack, Jul 24 '14 at 15:22
overload equals or supply an equality comparer. It will work. — cadrell0, Jul 24 '14 at 15:25

score 4 · Accepted Answer · answered Jul 24 '14 at 15:17

4

IEnumerable<MyObject> diffs = incomingList.Except(fullList);

answered Jul 24 '14 at 15:17

demoncodemonkey

5

Won't compile, LINQ results are not lists unless you call `.ToList()` – Ben Voigt Jul 24 '14 at 15:18
This also relies on `MyObject` properly implementing equality. – vcsjones Jul 24 '14 at 15:19
@BenVoigt Correct, that's an instance where `var` would have saved my butt :) (edited) – demoncodemonkey Jul 24 '14 at 15:19
I knew about except but doesn't even compile, that's why I posted it as question – CutHimSomeSlack Jul 24 '14 at 15:21
Except is in `System.Linq` namespace. – demoncodemonkey Jul 24 '14 at 15:22
2

@CutHimSomeSlack Then you need to be more clear in your question about what you have tried. `Except` works fine (assuming equality is implemented). – vcsjones Jul 24 '14 at 15:22
@vcsjones : Do you see it implemented in my code? No! So no it is not implemented because I don't know about it and that's probably where help is needed maybe?!!! – CutHimSomeSlack Jul 24 '14 at 15:24

score 3 · Answer 2 · answered Jul 24 '14 at 15:18

3

Enumerable.Except is what you after

var result = incomingList.Except(fullList);

answered Jul 24 '14 at 15:18

huMpty duMpty

1

Except does not compile. – CutHimSomeSlack Jul 24 '14 at 15:20
oh sorry, my bad...yeah that should work. I need some coffee :) – CutHimSomeSlack Jul 24 '14 at 15:29
@huMptyduMpty no I meant CHSS's MyObject, in the OP :) – demoncodemonkey Jul 24 '14 at 15:29

2 Answers2