Prasad Prasad - 21 days ago 5
C# Question

Remove duplicates in the list using linq

I have a class

Items
with
properties (Id, Name, Code, Price)
.

The List of
Items
is populated with duplicated items.

For ex.:

1 Item1 IT00001 $100
2 Item2 IT00002 $200
3 Item3 IT00003 $150
1 Item1 IT00001 $100
3 Item3 IT00003 $150


How to remove the duplicates in the list using linq?

Answer
var distinctItems = items.Distinct();

To match on only some of the properties, create a custom equality comparer, e.g.:

class DistinctItemComparer : IEqualityComparer<Item> {

    public bool Equals(Item x, Item y) {
        return x.Id == y.Id &&
            x.Name == y.Name &&
            x.Code == y.Code &&
            x.Price == y.Price;
    }

    public int GetHashCode(Item obj) {
        return obj.Id.GetHashCode() ^
            obj.Name.GetHashCode() ^
            obj.Code.GetHashCode() ^
            obj.Price.GetHashCode();
    }
}

Then use it like this:

var distinctItems = items.Distinct(new DistinctItemComparer());