Find Distinct elements from a List C#

Question

I have a class say named Product

public class Product
{
    public string Name{ get; set; }

    public int ProductId{ get; set; }

}

I have a list of Products, with same Name, but different ProductId.

I want to get distinct products from the list on product.Name

i.e. if the list is

var fullproductList = {
        Name: product,
        ProductId: 1
    }, {
        Name: product,
        ProductId: 2
    }, {
        Name: product,
        ProductId: 3
    };

I want any one the above product.

I want to achieve this without looping like this:

List<Product> distinctProducts= new List<Product>();

var distictproductName=fullSubjectList.Select(x => x.Name).Distinct().ToList();

foreach (var item in distictproductName)
{
    distinctProducts.Add(fullproductList.Where(x=>x.Name==item).FirstOrDefault());
}

Any suggestions?

gdoron · Accepted Answer · 2013-03-21T05:42:36.520

9

By using MoreLinq you can use Distinct with lambda:

fullSubjectList.DistinctBy(x => x.Name).ToList();

edited Mar 21 '13 at 05:42

answered Mar 21 '13 at 04:59

gdoron

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Neat! Am going to add MoreLinq to my project today! – Srikanth Venugopalan Mar 21 '13 at 05:03
You could also check the source code of that particular method: https://code.google.com/p/morelinq/source/browse/MoreLinq/DistinctBy.cs – Tx3 Mar 21 '13 at 05:05
@gdoron Several fields in DistinctBy: res = res.DistinctBy(i => i.Name).DistinctBy(i => i.ProductId).ToList(); – Kiquenet Apr 03 '14 at 10:04

score 2 · Answer 2 · edited May 23 '17 at 11:57

2

Use linq with a group by on name. That will give you the distinct. Look at this answer for a few ideas : LINQ: Distinct values

edited May 23 '17 at 11:57

Community

1
1

answered Mar 21 '13 at 05:01

TGH

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+1. Note that `DistinctBy` from `MoreLinq` is going to be a bit more efficient though. See the comments in the source from that link. – Jonathon Reinhart Mar 21 '13 at 05:07
Interesting. I was not aware of that library. – TGH Mar 21 '13 at 05:09

Find Distinct elements from a List C#

2 Answers2