Create an Object for inner classes. 

class ABC{   
class XYZ{    
    private int x=10;
    }  
  public static void main(String... args){
        ABC.XYZ xx = new ABC().new XYZ();  
      System.out.println("Hello :: "+xx.x);
 ///Why is this allowed??   
 }}
 
The inner class is just a way to cleanly separate some functionality that really belongs to the original outer class. They are intended to be used when you have 2 requirements:
  1. Some piece of functionality in your outer class would be most clear if it was implemented in a separate class.
  2. Even though it's in a separate class, the functionality is very closely tied to way that the outer class works.
Given these requirements, inner classes have full access to their outer class. Since they're basically a member of the outer class, it makes sense that they have access to methods and attributes of the outer class -- including privates.


 

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