Let's say we have 2 sets
A = [ PersonA,PersonB];
B = [ ManagerZ,ManagerT,ManagerY];
Result : ManagerT,ManagerY
There exists One to One mapping between the objects in A and the objects in B. I'm interested in those objects in B for which exists such an entry in A.
For completeness let's say we are matching on property named Name
Try following
SetB.Where(b => SetA.Any(a => a.Name == b.Name))
You have to perform a join on both lists:
var query =
from person in persons
join manager in managers on person.Name equals manager.Name
select new { Person = person, Manager = manager };
This will select all data from your Person-dataset together with the corresponding data from Manager-dataset.
Alternativly you can flatten the results into a datatype providing the whole data for every match:
select new { Name = person.Name, Age = person.Age, Departement = Manager.Departement }
Or if you´re only interested on the items from B which match use simply select manager.
Try with this code:
List<BType> result = B.Where(x >= A.Exists(y => y.Name == x.Name)).ToList();
In this way you mantain only managers that exists in people list.
A is a List<Person> as Exists is an instance method of List<T>.Also you can use Intersect. Example:
public class Person
{
public string Name { get; set; }
}
public class PersonEqualityComparer : IEqualityComparer<Person>
{
public bool Equals(Person x, Person y)
{
return x.Name.Equals(x.Name);
}
public int GetHashCode(Person obj)
{
return obj.Name.GetHashCode();
}
}
And now you can use:
var persons = new List<Person>() { new Person { Name = "John" } };
var managers = new List<Person>() { new Person { Name = "John" } };
var results = persons.Intersect(managers, new PersonEqualityComparer());
If you want compare two different class just edit Comparer.
bfrom setBfor which there exists an objectain setAsuch thata.Name == b.Name?SetA.Where(el => SetA.Any(a => a.Name == el.Name)