Comparison of Object Lists - C#

Question

I need to compare 2 lists of objects that were populated via database, as classes below:

public class Ausente
{
    public ObjectId Id { get; set; }
    public Int32 RA { get; set; }
}

public class AlunoEstagio
{
    public ObjectId Id { get; set; }
    public Int32 RA { get; set; }
    public String ALUNO { get; set; }
    public Int32 PERIODO { get; set; }
    public String DISCIPLINA { get; set; }
    public char CONCEITO { get; set; }
}

List 1 will receive the Missing object, list 2 will receive the Student Stage object.

I would like to compare the 2 lists so that when there is a List 1 RA attribute present in List 2, the corresponding List 2 object is added in a third list (List 3).

I have no idea how to make this comparison, could help me?

Answer 1

If the two guys were the same, you could use the Intersect, but as they are not, I think the code below does what you need:

var list3 = from l1 in list1
            join l2 in list2 on l1.RA equals l2.RA
            select new
            {
                l1,
                l2
            };

Where list1 and list2 are of the type List<Ausente> and List<AlunoEstagio> respectively.