problem in inheritance in java

general
,
1

class C{
int a=5;
}
class P{
C c=new C();
}
class d extends P{
void change(){
c.a=7;
new e().show();
}
}
class e extends P{

        void show(){
            System.out.println(c.a);
        }
    }
    class A{
        public static void main(String...args){
           new d().change();
        }
    }
The o/p of this code is 5

But since we have created only one object of class c which is common to both class d and class e the o/p should be 7.

and when I replace precede the statement C c=new C(); with static keyword o/p is 7.

Can any one explain what is happening.

2

Hi,
First we need to understand the concept of static and instance variables

  1. Static
    This variables are initialized when class is loaded
  2. Instance
    This variables are initialized when Object is created
    Class loads only once but we can create multiple objects for a class.
    In the above example, C is instance is variable and gets created & initialized in the following cases
  3. If you create an object for Class p
  4. If you create an object for any one of the subclass
    Now it creates two new objects for P from class d and e
3

@tdeekshith

thanks

4

Very clear explanation. This is really an amazing explanation and came to know that why java does not support Multiple inheritance. Dissertation-Time. Keep Posting you are doing a good work.