having protected variables in interfaces?

[Justin Fox]

ok, i was wondering can you have protected variables that you

can modify in your classes?

umm, somethin like

    
interface myinterface
{
protected x,y,z;
 
public void drawFireball(Graphics g);
 
public void drawFighter(Graphics g);
 
}
 
ok and if i can do this, how do i make it to where, when i modify the 
 
variables, they change in each class that implements myinterface?
 

[Alana Sparx]

I'm fairly sure interfaces only allow you to have public, static and/or final modifiers for methods and primitives.

The compiler should tell you though.....

[Peter Chase]

You can't have any fields/variables in an interface, except constants (public static final). You can't have any access modifiers, except public.

Generally, you should not bother writing the "public" in interfaces, as everything is public anyway. Well, perhaps this is a matter of style, but I think so.

[Vinayak patil]

I have a question related to variables in interfaces:

Why do we have to initialize the variables when we declare them in an interface? And why are they treated as final variables?

Thanks in advance,
Vinayak

[Ernest Friedman-Hill]

Because they are not "variables" -- that's the whole point. They're constants. Interfaces can't include any per-instance data.