What is OfType extension Method how to use?

Yes, In Linq(language Integriated Query) we have may extension to work with query based operations.

In linq all clauses are  are defined as Extension methods. Like where clause -àwhere extension…ect

Ex:

Linq to Objects

Quering an object using linq is called linq to object.

Prepare an object then query from linq style.

static class Enumerable

{

public static IEnumerable<TResult> OfType<TResult>(this IEnumerable source);

}

ArrayList is one non-generic collection so this collection contains all types of data.

ArrayList arr = new ArrayList();

           arr.Add(5);              //int

           arr.Add("efgh");     //string

           arr.Add(10);           // int

           arr.Add("mnop");  // preparing an object

          var x = from n in arr.OfType<int>()  where n == 10 select n;

          Console.WriteLine(x);

So we have to

 Filters the elements of an System.Collections.IEnumerable based on a specified type.

Like

          OfType<int> then filter the specified value from all int types.

          OfType<string> then filter the specified value from all string types.

           OfType<double> then filter the specified value from all double types.

………………..ect.

Coming to Generic Collections Like List<T> types not required this OfType<Tsoruce> methods

Why because which accepts all the elements same type.

List<int> arrlist = new List<int>();

           arrlist.Add(10);

           arrlist.Add(20);

           arrlist.Add(30);

  var y = from m in arrlist where m == 10 select m;

not requried OfType<TResult>() method here because of list is Strongly typed or Generic Collecton.