LINQ Cast Operator

Casts the elements of a sequence to a specified type

The Cast operator enumerates the source sequence and tries to yield each item, cast to type T. In the case of failure, an InvalidCastException error will be thrown.

public static IEnumerable<T> Cast<T>( this IEnumerable source);

Because of its signature, which accepts any IEnumerable sequence, this method can be used to convert old nongeneric types to newer IEnumerable<T> types. This conversion makes it possible to query these types with LINQ even if the types are unaware of LINQ.

System.Collections.ArrayList fruits = new System.Collections.ArrayList();
            fruits.Add("apple");
            fruits.Add("mango");

           IEnumerable<string> query =
                 fruits.Cast<string>().Select(fruit => fruit);

             foreach (string fruit in query)
            {
               Console.WriteLine(fruit);
             }

             // This code produces the following output:
            //
            // apple
            // mango