How to get a distinct list from a List of objects?

Question

I have a List<MyClass> someList.

class MyClass {     public int Prop1...     public int Prop2...     public int Prop3... } 

I would like to know how to get a new distinct List<MyClass> distinctList from List<MyClass> someList, but only comparing it to Prop2.

Answer 1

You can emulate the effect of DistinctBy using GroupBy and then just using the first entry in each group. Might be a bit slower that the other implementations though.

someList.GroupBy(elem=>elem.Prop2).Select(group=>group.First());