What is the access modifier on a regular inner class?

[Gary Marshall]

All:
Here is the code for question # 12, chapter 8 ("Inner Classes") from the K&B SCJP book:

   
import java.util.*;
public class Pockets {
	public static void main(String[] args){
		String [] sa = {"nickel", "button", "key", "lint"};
		Sorter s = new Sorter();
		for (String s2: sa) System.out.print(s2 + " ");
		Arrays.sort(sa,s);
		System.out.println();
		for (String s2: sa) System.out.print(s2 + " ");
	}
	class Sorter  implements Comparator<String>{
		public int compare(String a, String b){
			return b.compareTo(a);
		}
	}
}
 

The book states that for this code to compile cleanly the inner class Sorter must be declared static. OK, so that means that class Sorter as coded is not static, so then what is its access modifier? Is its access modifier default since there was no access modifier provided? Does this mean that all regular inner classes have default access, unless an access modifier is provided?

I think I know the answer to this but I need someone who knows much more than I do to confirm.

Thank you all for your time.
G

[Stephan van Hulst]

Yes, Sorter has default (package private) access. Keep in mind that this has nothing to do with static, because static is not an access modifier. Declaring Sorter as static still means it has package private access.

[Kushan Athukorala]

Hi Gary,

You are talking about two different aspects. In your example why the class is not compiled is not because of insufficient access privileges. But because of "static methods can only access static variables or methods".

Consider regular inner class as merely a member in the outer class. If you think like that we can specify any access modifier for regular inner class. That is coderanch, default, protected and private are valid access modifiers for regular inner classes.

Thanks,
Kushan