Separate repeated values in a list

Question

I have a list like this:

[1,1,1,2,2,1,5,3,4,3,4]

How to generate a new list with only one value of each:

[1,2,3,4,5]

The first list is a List<int> the second can come in any kind of list.

Answer 1

By mathematical definition, a set is a structure in which each element appears only once. In C#, a set is represented by HashSet<T>.

Generating a HashSet<int> from your list, you will have the elements without repetition:

var conjunto = new HashSet<int>(lista);

See a demonstration here.

Answer 2

Use the Distinct to remove duplicated items, generating a new object.

List<int> novaListaDeInteiros = listaDeInteirosVelha.Distinct().ToList();

This will return a sequence List<int> filled without repeating the data.

Answer 3

Use the Distinct to return the different elements from your list.

using System.Linq;

List<int> lista = new List<int> { 1, 1, 1, 2, 2, 1, 5, 3, 4, 3, 4 } ;
lista.Distinct();

Answer 4

The function Distinct of Linq deletes duplicate data from a list in . Net Framework:

var lista = new List<int> {1,1,1,2,2,1,5,3,4,3,4};
var listaSemDuplicidade = lista.Distinct();

A functional example can be seen here.