title: What is use of Parent object instantiating with child class
body: <p>Please tell me what is of parent object instantiating with child class like:</p>
  
  <pre><code> public class A
      {
          public A()
          {
              Console.WriteLine("A");
          }
          public virtual void method()
          {
              Console.WriteLine("AM");
          }
  
      }
      public class B : A
      {
          public B()
          {
              Console.WriteLine("B");
  
          }
          public new void method()
          {
              Console.WriteLine("BM");
  
          }
          public void method1()
          {
              Console.WriteLine("BM1");
          }
      }
  
   class Program
      {
          static void Main(string[] args)
          {
              A obj = new B();// what is use of it?
              obj.method();              
              Console.Read();
          }
          private void methodP1()
          {
  
          }
      }
  </code></pre>
  
  <p>please tell me what is use of
  Parent obj = new Child();
  as i we can only call to only public methods of parent class which is possible using 
  Parent obj = new Parent();</p>
  
  <p>is it possible: Child obj = new Parent() ?</p>