Sort list after lastname and than after firstname in C#

Question

How can I enhance my following function

personList.Sort (delegate (Person firstPerson, Person secondPerson) {
    return firstPerson.Lastname.CompareTo (secondPerson.Lastname);
});

to first sort after last name and than after first name?

Answer 1

You can check if Lastnames are equal and do the comparison accordingly:

personList.Sort (delegate (Person firstPerson, Person secondPerson) 
{
   if(firstPerson.Lastname == secondPersonLasname)
       return firstPerson.Firstname.CompareTo(secondPerson.Firstname);

   return firstPerson.Lastname.CompareTo (secondPerson.Lastname);
});

If you would like to use Linq there is also another way:

personList = personList.OrderBy(p => p.LastName).ThenBy(p => p.Firstname).ToList();