About Question enthuware.ocpjp.v7.2.1421 :

[alex]

Hi,

Why an option Insider in = os.new Insider(); is illegal?
Compiler allows me to insert this line.

Description says next: You cannot refer to Insider class directly. For all purposes, its name is Outsider.Insider.
But I can refer to Insider class directly.

Regards,
Alex

[admin]

Are you sure you are running the code exactly as given? I just tried it and it didn't compile.

HTH,
Paul.

[alex]

Hi Paul,

Sorry, there was one blooper.
Actually I could use Insider in = os.new Insider(); if I would have appropriate import Outsider.Insider;
But that is not mentioned in context.

[renatumb]

Depends on the context, but

Code: Select all

Insider in = os.new Insider()

is not totally illegal.

because If you imported also the Inner Class, it would work, something as such:
import Outter.* ;

http://docs.oracle.com/javase/tutorial/ ... epkgs.html

I think you should change a little bit the explanation, because it causes some confusion...

[admin]

I am not sure I follow what you are saying. Can you give complete code listing to explain what you mean? As per the code given in the question, Insider in = os.new Insider() is invalid.

HTH,
Paul.

[renatumb]

Sorry, I forgot to say that is necessary the package, as such: import package.class.*

I wrote this class to show you what i mean:

Code: Select all

package p1;

import p1.Outter.*; // This is necessary, wihout it, Inner Classes don't work !! 
// It is importing only the Inner Classes, like "import static"

public class TestClass {
    public static void main(String[] args) {
        
        Outter out = new Outter();
        
        InnerPublic     in1 = out.new InnerPublic(); // OK
        InnerDefault    in2 = out.new InnerDefault();    // dont work out of p1
        InnerProtected  in3 = out.new InnerProtected();  // dont work out of p1
        //InnerPrivate    in4;
    }
}

Code: Select all

package p1;

import p1.Outter.*; // This is necessary, wihout it, Inner Classes don't work !! 
// It is importing only the Inner Classes, like "import static"

public class TestClass {
    public static void main(String[] args) {
        
        Outter out = new Outter();
        
        InnerPublic     in1 = out.new InnerPublic(); // OK
        InnerDefault    in2;    // dont work out of p1
        InnerProtected  in3;    // dont work out of p1
        //InnerPrivate    in4;
    }
}

[admin]

I see what you are saying. You are right. This has now been added to the explanation.

thank you for your feedback,
Paul.