This is supposed to be a class instance creation expression

http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#15.9

 so

{ intvar = 1; }

 needs to be a class body, which only may contain
 ClassBodyDeclarations.

http://java.sun.com/docs/books/jls/third_edition/html/classes.html#8.1.6

 "intvar = 1;" is not such a ClassBodyDeclaration.

 A ClassBodyDeclaration is one of

InstanceInitializer
StaticInitializer
ConstructorDeclaration
FieldDeclaration
MethodDeclaration
ClassDeclaration                       
InterfaceDeclaration
;       

This declares the field intvar (and initializes it.)

This is a statement that needs to be inside a method, but isn't.

There's nothing special about anonymous classes here; it's the same error as
in

   class HasError
   {
       int intvar = 0;
       intvar = 1;            // needs to be inside some method
   }

Have a look at the structure of testclass. It declares one field variable
intvar, with the value 0 being assigned by the default constructor
implicitly. This line is ok.

But the assignment intvar=1 is neither a new field declaration, nor is the
code inside a constructor or method. Therefore the compiler fails.

Hiran Chaudhuri

Hi,

Can someone please explain why the code below works? in particular
printing of the "memberInt" variable within instant initializer of the
anonymous class.

The anonymous class is within a static context but yet is accessing a
non static variable - confused :(

Possible theory; inner classes has implicit ref to enclosing class?
but we are in a static context?

public class TestAnony {
 int memberInt = 123;

 public static void main (String a[]) {

   new TestAnony() { // anonymouse class declaration

     { // instant initializer
       System.err.println(memberInt); // Why is this OK?
     }

   };

   class SomeLocal { // local class declaration
     public SomeLocal() { // constructor
       //System.err.println(memberInt); //static Ctx. this won't work
     }
   }

 } // end of main method

}

tia