Casting parent class to a child class

Question

Hi,
I have a static method which returns a class called parent. Now I want to cast it it's child class. There are no compilation errors, but at runtime it's throwing me ClassCastException. This is what I'm doing.
public Parent getObject() {
Parent p = new Parent();
return p;
Child c = (Child) getObject();What is wrong with this code? I couldn't figure it out.
Any help will be appreciated.
Thanks,

Answer 1

Parent p1 = new Parent(); // 1
Parent p2 = new Child(); // 2
Child c1 = new Parent(); // 3
Child c2 = new Child(); // 4
Parent p1 = (Parent)c1; // 5
Parnet p2 = (Parent)c2; // 6
Child c3 = (Child)p1; // 7
Child c4 = (Child)p2; // 81: Ok.
2: Ok. Every Child IS-A parent.
3: Compile time error. A Parent object is not a Child.
4: Ok.
5: Ok, because every Child IS-A parent, and the cast is unnecessary. (Though since 3 is illegal a compile time we wouldn't actually have this situation.)
6: Ok, and the cast is unnecessary, because every Child IS-A Parent.
7: ClassCastException at runtime. The object is not a Child.
8: Ok.