List 'Except' comparison - ignore case

Question

I have two lists and I want to compare them and get the differences, while ignoring any case differences.

I have used the following code to get the differences between the two lists but it does not ignore case differences.

IEnumerable<string> diff = list1.Except(list2);
List<string> differenceList = diff.ToList<string>();

I tried this:

IEnumerable<string> diff = list1.Except(list2, StringComparison.OrdinalIgnoreCase);

but Except does not seem to be having a string case check of that sort (so error). I'm hoping there's a work around.

That should probably be a `StringComparer`, not `StringComparison`. Pay attention to the types... — Jeff Mercado, Sep 05 '14 at 06:27
See the [Except](http://msdn.microsoft.com/library/bb336390.aspx) overload with an [IEqualityComparer](http://msdn.microsoft.com/library/ms132151.aspx). As @JeffMercado said, there can already several `IEqualityComparer` be found under [StringComparer](http://msdn.microsoft.com/library/system.stringcomparer.aspx) — Corak, Sep 05 '14 at 06:31
Thanks all :) I can't believe I didn't try `StringComparer`. — john, Sep 05 '14 at 06:33

score 48 · Answer 1 · edited Oct 26 '15 at 11:40

48

Try this :)

List<string> except = list1.Except(list2, StringComparer.OrdinalIgnoreCase).ToList();

Worked for me!

edited Oct 26 '15 at 11:40

JoeBilly

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answered Sep 05 '14 at 08:01

Damitha Shyamantha

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Thank you @joebilly for adding that leading space : ) – Damitha Shyamantha Mar 22 '21 at 06:41
Thanks @joebilly – Tiago Oct 07 '21 at 21:46

score 19 · Accepted Answer · edited Apr 02 '18 at 08:36

19

Here's what worked:

IEnumerable<string> differenceQuery = inputTable.Except(strArrList,
                                                        StringComparer.OrdinalIgnoreCase);

Used StringComparer instead of StringComparison.

edited Apr 02 '18 at 08:36

41686d6564 stands w. Palestine

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answered Sep 05 '14 at 07:24

john

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score -1 · Answer 3 · edited Dec 23 '22 at 17:27

-1

use StringComparer as shown below

Code:

list3 = list1.Except(list2,StringComparer.OrdinalIgnoreCase);

edited Dec 23 '22 at 17:27

Vince

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answered Apr 20 '20 at 08:17

Kundan

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List 'Except' comparison - ignore case

3 Answers3