How to merge two lists and remove duplicates

Question

Given I have two list like the following:

var listA = new List<string> { "test1", "test2", "test3" };
var listB = new List<string> { "test2", "test3", "test4" };

I want a third list with:

var listC = new List<string> { "test1", "test2", "test3", "test4"}

Is there a way to get this?

Possible duplicate of [Simplest way to form a union of two lists](http://stackoverflow.com/questions/13505672/simplest-way-to-form-a-union-of-two-lists) — dana, Jan 20 '17 at 15:24

score 28 · Accepted Answer · answered Jan 20 '17 at 15:21

28

Try the Union extension method.

var result = listA.Union(listB).ToList();

Union produces the set union of two sequences by using the default equality comparer so the result contains only distinct values from both lists.

answered Jan 20 '17 at 15:21

Damian

score 2 · Answer 2 · answered Jan 20 '17 at 15:19

2

listA.AddRange(listB).Distinct().ToList();

answered Jan 20 '17 at 15:19

score 2 · Answer 3 · answered Jan 20 '17 at 15:20

2

Use Concat() and then Distinct() Linq methods

listA.Concat(listB).Distinct().ToList();

answered Jan 20 '17 at 15:20

nobody

3 Answers3