// Demonstrate as.
//csc demo_as.cs
using System;
class A {}
class B : A {}
class CheckCast {
public static void Main() {
A a = new A();
B b = new B();
b = a as B; // cast, if possible
if(b==null)
Console.WriteLine("Cast b = (B) a is NOT allowed.");
else
Console.WriteLine("Cast b = (B) a is allowed");
}
}