Combining 2 lists and and remove duplicates .Output in a third list .My attempts do not work

Question

I always seem to have a problem when I need to compare 2 list and produce a 3rd list which include all unique items.I need to perform this quite often.

Attempt to re

Answer 1

Couldn't you do this by using the Concat and Distinct LINQ methods?

List listOne;
List listTwo;

List uniqueList = listOne.Concat(listTwo).Distinct().ToList(); 

If necessary, you can use the Distinct() overload that takes an IEqualityComparer to create custom equality comparisons