class inheritance and static variable question

[warren li]

Hi,

From the <<SCJP 5 Study Guide>> book Page 162, Qn 11.
In case you don't have the book, here is the code:

class Uber{
    static int y = 2;
    Uber(int x){
        this();
        y = y * 2;
    }
 
    Uber(){
        y++;
    }
}
 
class Minor extends Uber {
    Minor(){
        super(y);
        y = y + 3;
    }
 
    public static void main( String[] args ){
        new Minor();
        System.out.println(y);
    }
}

This code compiles fine.

I am really confused by the access to 'y' in Minor's constructor( the line super(y); ), how do you explain it?
My understanding is, y is static in Uber class and is not inherited in class Minor 'coz it is static. but if I change it to super(Minor.y);, it still compiles.

anyone please enlighten me? Thanks.

[Peter Chase]

Not an advanced Java question.

I guess that the two classes are in the same package. Since "y" has no access specifier, it has package access. Therefore, it can be accessed by any class in the same package.

Being static does not affect the inheritance of "y".

[warren li]

so you mean static variables/methods are also inherited?
this is rather contrary to my belief.

[Peter Chase]

Originally posted by warren li:
so you mean static variables/methods are also inherited?
this is rather contrary to my belief.

Well, you'd best update your belief by reading the language specs or a good book! The access to static fields and methods is controlled by their access specifier, exactly like member fields and methods.

[Kevin Huang]

Static field is inherited too.
But there will be 2 different copies in the parent and child classes.

Kevin Huang
SCJP, SCWCD, SCBCD
MCP, MCAD, MCSD

[Ken Blair]

Originally posted by Kevin Huang:
Static field is inherited too.
But there will be 2 different copies in the parent and child classes.

Kevin Huang
SCJP, SCWCD, SCBCD
MCP, MCAD, MCSD

There is only one copy and it belongs to the Class, not any particular instance.