How to call a private local class

Question

So, inside a bigger class, there is a local private class that i need to use for a method later on, but i don't know how to access it...

The private class, which i cannot change because it's part of the exercise, looks like this:

private class Counter 
 {
   String element;
   int frequency;             
   Counter (String element) 
   {
     this.element = element;
     frequency = 0;
   } 
   String element() {
       return this.element;
   }
 }

And the method I need to implement, which should add the Id with its frequency to the frequency list lf, looks like this:

private void update (String id, IList<Counter> lf) 
  {
      
  }

I´m trying to use the add method from the IList, but i don't know how to use a type Counter, since it is a privae class and I can't access it.

Welcome to Stackoverflow, please read [How To Ask](https://stackoverflow.com/help/how-to-ask). Pay special attention to [How To Create MCVE](https://stackoverflow.com/help/mcve). Make sure you tag your question with proper labels (programming language, relevant technologies etc). The more effort you'll put into posting a good question: one which is easy to read, understand and which is [on topic](https://stackoverflow.com/help/on-topic) - the chances are higher that it will attract the relevant people and you'll get help even faster. Good luck! — Nir Alfasi, May 27 '21 at 11:27
@DiegoDoe It's `private`. What you ask? It is __impossible__. The exercise is broken and cannot be completed, or, there's an important detail that you haven't included in this question. — rzwitserloot, May 27 '21 at 11:36

score 0 · Accepted Answer · 2021-05-27T12:12:46.023

Assuming the following starting class _{(NO, it is not the solution)}:

public class Bigger {

    // inner class should not be changed
    private class Counter {
        String element;
        int frequency;             

        Counter (String element) {
            this.element = element;
            frequency = 0;
        } 

        String element() {
            return this.element;
        }
    }

    private void update (String id, IList<Counter> lf) {
        // TODO 
    }
}

To access Counter inside of update, we can just write:

public class Bigger {
    // ...
    private void update (String id, IList<Counter> lf) {
        Counter counter = new Counter(id);
        // eventually call counter.element()
        // or accessfields like counter.frequency = 1;
        // TODO 
    }
}

^{Note: Counter is not a local class, but an inner class (I assumed one, since local classes cannot be declared private).}

The access to private inner classes and even to private members of such classes from within the same containing class, is allowed by JLS 6.6.1:

Otherwise, the member or constructor is declared private. Access is permitted only when the access occurs from within the body of the top level class or interface that encloses the declaration of the member or constructor.

How to call a private local class

1 Answers1