Query regarding LinQ to Objects

[RadKrish]

Hello All,

I seek your help in the following case.

I have a base class say ClassBase and two derived class deriving from ClassBase, say ClassD1 and ClassD2.

I have a collection (List) object which can store objects of type ClassBase

in my code I create several derived class objects(say in 100s) and store in the collection object as said above.

now at any give execution point I need to know how many instance of ClassD1 is stored in the collection object.

I understand that this can be achieved using using writing a query using LinQ to objects, but couldnt work out the exact query, could some one help or educate me on this?? please...

Regards
Radkrish

[boudino]

list.Count(i => i.GetType() == typeof(ClassD1));

[SAAM007]

This is the first time I tried LinQ but here is something that worked for me:

        class ClassBase { }
        class ClassD1 : ClassBase { }
        class ClassD2 : ClassBase { }

            var list = new List<ClassBase> { new ClassD1{} ,
                                             new ClassD1{} ,
                                             new ClassD1{} ,
                                             new ClassD2{} ,
                                             new ClassD1{} ,
                                             new ClassD2{} ,
                                             new ClassD2{} ,
                                             new ClassD1{}};
            var Found = from o in list
                        group o by o.GetType();

            foreach (var clsType in Found)
                Console.WriteLine(clsType.Key +" "+ clsType.Count());

If you need to get the amounts frequently, you should consider wrap a list with counters for each type (using Dictionary<Type, int> for counters and override add/delete/clear)

[RadKrish]

Hello boudino and SAAM007,
Thanks a lot and both the solution are working for me.

Regards
RadKrish