java.lang.ClassException: A cannot be cast into B

Question

I implemented this code:

class A {
    //some code
}
class B extends A {
    // some code
}

class C {
    public static void main(String []args)
    {
              


        

Answer 1

The name it self implies the compiler will just looks at compile-time type of the expression.

It does not do assumptions on the runtime type of the expression.

http://docs.oracle.com/javase/specs/jls/se7/html/jls-5.html#jls-5.5.1

Coming to real problem

You cannot cast A to B.You can cast B to A.When you have a Mango,You have Fruit.But when you have a Fruit,It not mean that You have a Mango.