Declare non-static "local class" within static method

[Paul Salerno]

I have witnessed code that does illustrate the definition of a non static local inner class within a static method:

  
class Outer
{
   static void myStaticMethod()
   {
      final int r = 200;
      class LocalinStatic
      {
         int k = r;
      }
   }
}

Invoked from another method like this correct?
outer.LocalinStatic myInner = new Outer(). new LocalinStatic()
Since I've only seen one example of this, I want to be sure if, A. its legal, B. How to invoke
Thanks All!

[Ruchi Kolla]

You cannnot invoke the class which is declared inside the method. You can only invoke inner classes declared inside the main class as shown below.
Here is an example:
class Test
{
static void myStaticMethod()
{
final int r = 200;
class LocalinStatic
{
int k = r;
}
}
class Inner
{
//some code
}

public static void main(String args[])
{
Test.Inner inner = (new Test()).new Inner();
Test.LocalinStatic inner1 = (new Test()).new LocalinStatic();//compile time error.
}
}

[Marilyn de Queiroz]

> Invoked from another method like this correct?
>
> outer.LocalinStatic myInner = new Outer(). new LocalinStatic()
>
> Since I've only seen one example of this, I want to be sure if, A. its legal, B. How to invoke.

class Outer
{
    static void myStaticMethod()
    {
        final int r = 200 ;
        
        class LocalinStatic
        {
            int k = r ;
        }
        
        LocalinStatic lis = new LocalinStatic();
    }
   
    public static void main( String[] args )
    {
        new Outer().myStaticMethod();
    }
} 

The class LocalinStatic is legal.

The call:
outer.LocalinStatic myInner = new Outer(). new LocalinStatic();
is not legal.

You cannot access a local variable from outside the method. You cannot access the local variable 'r' from outside myStaticMethod, and you cannot access the local class from outside myStaticMethod.

[Paul Salerno]

Marilyn,

You cannot access a local variable from outside the method. You cannot access the local variable 'r' from outside myStaticMethod, and you cannot access the local class from outside myStaticMethod

What about the case where the local inner class is within a non static method vs static. This is one of Rob's codes, Thanks Rob

Class Outer
{
   private int cx=0;
   int cy=0;
   void myMethod(int arg, final int fv)
   {
      int x = 0
      final int y = 0
      class Inner
      {
         int k = cx
         System.out.println(cx)
         System.out.println(cy)
         System.out.println(fv)
         System.out.println(y)
      }
   }
}

Can we access the local var K?

[Rob Ross]

Your class Inner is a class definition; you haven't actually *created* any Inner objects.
The scope of this declaration is the method in which it is declared. That means you can only create an Inner object in the method myMethod().
In the myMethod() method, you could write (AFTER the Inner class definition)
Inner anInner = new Inner();
Then you have an Inner object, and you can write
anInner.k
and access that member.
Note, your Inner class won't compile. Those println() statements aren't in a method, and so they're not legal in that context.

Also, K is NOT a local variable. It's an instance field of class Inner.

Rob

[Paul Salerno]

Note, your Inner class won't compile. Those println() statements aren't in a method, and so they're not legal in that context.
What you mean Rob?
Its clear that local inner classes within methods aren't available outside the scope of the method unless we create an inner class object as you mentioned.
Sanka

[Rob Ross]

Every class has the same internal structure Paul.

 class foo{         
    int k = cx         
    System.out.println(cx)
    System.out.println(cy)
    System.out.println(fv)
    System.out.println(y)      
}

Is this a legal class?
Will it compile?
Why or why not?
Why would an inner class behave any differently in this regard?

Rob