instance variables initialization

[ghostrider]

Class Dog
{

Dog a;
Dog b = new Dog();
a=b;\\error class a not found
}
But why cannot we initialize instance variables in two steps?

[Norm]

The assignment statement needs to be in a method or perhaps a static block.

[ghostrider]

Can you please give me the reason behind this?

[sehudson]

When you define a class, it is generally made up of 3 parts:
-Member variables
-Constructor(s)
-Methods(setters/getters and other private/public methods)

You may also have inner classes and a few other parts, but this is generally the makeup.

As far as variable initialization goes, if you want to do it outside of a method or the constructor, I believe you have to
declare and initialize it in one step:

Dog b = new Dog();

If you want to declare and initialize a variable in 2 separate steps(as you have)...

Dog a; //declare
Dog b = new Dog();
a = b; //initialize

...the declaration can happen outside of the constructor or
method like you have it, but, the initialization has to take place inside of the constructor or a method.

I may not be explaining it correctly, or this may be confusing, but I think that is the general principle.

[Junky]

<nitpick>
Declaring a Dog variable within the Dog class usually causes problems. Only do this if you are 100% sure you know what you are doing. Why is it a problem? It can lead to infinite recursion, ie Creating a Dog creates another Dog inside, which creates another Dog, which creates another Dog and so on.

[pbrockway2]

Yes, could be a problem with Dog. Not so, Flea, however, according to The Siphonaptera.

[DarrylBurke]

ie Creating a Dog creates another Dog inside, which creates another Dog, which creates another Dog and so on.

Happens every year or so though. And not just one -- usually 5 or 6.

db