Private Class Declaration

[AtulTiwari]

Can any one here who tell me that why we can not Declare a class or Interface as Private or Protected.

I have just compiled a class as

private class abc{
}

then the compiler throw an error that private is not allowed here

So can any one plz explain me the reason behind that?

[DeMan]

Java is not my strongest language, however I would suggest that it doesn't make sense for a class to be private or protected, because it means that (almost) noone can see it.......

[r035198x]

Can any one here who tell me that why we can not Declare a class or Interface as Private or Protected.

I have just compiled a class as

private class abc{
}

then the compiler throw an error that private is not allowed here

So can any one plz explain me the reason behind that?

A class can be decared as protected, in which case it will only be available in the package in which it is declared.
A private class does not make sense and is not allowed.
You can read this article for a descrption of some of this stuff.

[AtulTiwari]

Java is not my strongest language, however I would suggest that it doesn't make sense for a class to be private or protected, because it means that (almost) noone can see it.......

Thanks for your Reply,

Actually I am also thinking the same from my own, but i have Posted the Question just bcz to know that my thinking is right or wrong.

But if any one wants to explain something more then, Most Welcome,

Thanks Again

[DeMan]

I think r0 has probably provided a better explanation and a very useful link......

[r035198x]

I think r0 has probably provided a better explanation and a very useful link......

You call me r0 one more time and you can consider yourself banned.

[KishoreM]

Hi,

first thing It is not right that you can not create a private or protected class.....you can create but this class should not be Top level class in the file means you can create private/protected innerclasses.

second thing what is the sense to create a Top level class as private/protected because anyway it is not going to be accessed by outside programs.

regards,

Kishore M

[r035198x]

Hi,

first thing It is not right that you can not create a private or protected class.....you can create but this class should not be Top level class in the file means you can create private/protected innerclasses.

second thing what is the sense to create a Top level class as private/protected because anyway it is not going to be accessed by outside programs.

regards,

Kishore M

OK.
A protected class can be accessed by other programs within the same package that that class has been defined (so it can be defined top level).
A private top level class is not allowed because that's not going to be of any use but you can declare a private class as a member of another class.

[DeMan]

You call me r0 one more time and you can consider yourself banned.

sorry, like a phone number I forgot the digits.......

[AtulTiwari]

sorry, like a phone number I forgot the digits.......

Sorry sorry but i found a Quote in the link given here
http://www.thescripts.com/forum/thread641524.html

and it will explaining that

Class structure

A class declaration starts with a modifier which can be any of
public, protected, private, abstract, static, strictfp, final.
To get us started we'll look at the public and protected modifiers first.
Java classes are encapsulated into packages. Classes in one package can only access public classes in another package. Protected classes are accessible only within the package that they have been defined. If you do not include a modifier, protected access is assumed. The class is put inside the default package which is automatically created for you.
You should always put your classes in a package. Here is the rest of the structure of a Java class:

Modifier(s) class ClassName {
members(methods, fields, nested classes and interfaces)
constructors
static initializers

}



Now what you all says about this article?

[AtulTiwari]

OK.
A protected class can be accessed by other programs within the same package that that class has been defined (so it can be defined top level).
A private top level class is not allowed because that's not going to be of any use but you can declare a private class as a member of another class.

Sorry r0 i want to disturb you here but we can not use protected as modifier for top level class and it will give compile time error.

[r035198x]

Sorry sorry but i found a Quote in the link given here
http://www.thescripts.com/forum/thread641524.html

and it will explaining that

Class structure

A class declaration starts with a modifier which can be any of
public, protected, private, abstract, static, strictfp, final.
To get us started we'll look at the public and protected modifiers first.
Java classes are encapsulated into packages. Classes in one package can only access public classes in another package. Protected classes are accessible only within the package that they have been defined. If you do not include a modifier, protected access is assumed. The class is put inside the default package which is automatically created for you.
You should always put your classes in a package. Here is the rest of the structure of a Java class:

Modifier(s) class ClassName {
members(methods, fields, nested classes and interfaces)
constructors
static initializers

}



Now what you all says about this article?

I hope you're not starting to get confused.
A private class cannot be top level. It can only be declared inside another class. That's why private was listed there as one of the possible class modifiers.

[AtulTiwari]

I hope you're not starting to get confused.
A private class cannot be top level. It can only be declared inside another class. That's why private was listed there as one of the possible class modifiers.

thanks to all of you for your kind discussion here.
I really got very useful knowledge from here.

[r035198x]

Sorry r0 i want to disturb you here but we can not use protected as modifier for top level class and it will give compile time error.

Yack, I've really messed things up now.

protected won't work for top level class alright.
If you leave a class without a modifier (and define no package), it is placed in the default package and is accessible only inside that default package (sort of protected access for that class).
But you're all right, protected specifier won't work for top level and I've been telling it wrong there.

Edit: You can call me r0 now after that mistake.

[DeMan]

.....(does that include me)

[praveen2gupta]

class is having only Two access Modifiers

1. default (neet not to write)
2. Public

any other access modifiers are not allowed with classes.

[r035198x]

.....(does that include me)

You do that, you'd be banned before you even hit the Submit Reply button.

[r035198x]

class is having only Two access Modifiers

1. default (neet not to write)
2. Public

any other access modifiers are not allowed with classes.

Here we go again, unless it's inside another class

package x;
class a {
    private class b {
    }
    protected class c {
    }
}

[AtulTiwari]

Here we go again, unless it's inside another class

package x;
class a {
    private class b {
    }
    protected class c {
    }
}

This time You are all Right Dear r0

[JosAH]

Just to sum it all up; there are top level classes and nested classes. Top level
classes have either package scope or they are public.

Nested classes can be static or not which is not relevant for this discussion.
Nested classes can either be private, protected, package scope or public.
Anonymous classes (e.g. those small Listener or Observer classes) have to be
made visible by the surrounding class otherwise they don't exist according to the
outside world, whatever that may be.

It doesn't make sense for top level classes to be private because nothing else
can reach them. The same goes for protected top level classes, i.e. only the
class itself can reach it or a subclass thereof. But something else has to start
the whole thing going but it isn't allowed to even point its finger at it, nor at a
subclass thereof.

kind regards,

Jos