Union, intersection and difference of C # List

Union --- Union

The union of the collection is to merge all the items of the two collections and remove the duplicates, as shown in the following figure:

 

 

 

1. List<int> ls1 = new List<int>() { 1,2,3,5,7,9 };
2. List<int> ls2 = new List<int>() { 2,4,6,8,9,10};
4. IEnumerable<int> unionLs = ls1.Union(ls2);
5. foreach (int item in unionLs)
6. {
7. Console.Write("{0}\t", item);
8. }

 

 

 

Intersection --- Intersect

The intersection of the set is the common item of the set, as shown in the following figure:

 

 

 

1. List<int> ls1 = new List<int>() { 1,2,3,5,7,9 };
2. List<int> ls2 = new List<int>() { 2,4,6,8,9,10};
5. IEnumerable<int> intersectLs = ls1.Intersect(ls2);
6. foreach (int item in intersectLs)
7. {
8. Console.Write("{0}\t",item);
9. }

 

 

 

 

Difference-Except

The difference of a set is to take all the items in the set but not in another set, as shown in the following figure:

 

 

 

 

List<int> ls1 = new List<int>() { 1,2,3,5,7,9 };

List<int> ls2 = new List<int>() { 2,4,6,8,9,10};

 

 

IEnumerable<int> exceptLs = ls1.Except(ls2);

foreach (int item in exceptLs)

{

Console.Write("{0}\t", item);

}