From sunś Inner Class Exampel

Question

Hi Have a questions about the exampel
[http://java.sun.com/docs/books/tutorial/java/javaOO/innerclasses.html]
public void printEven() {
        //print out values of even indices of the array
        InnerEvenIterator iterator = this.new InnerEvenIterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.getNext() + " ");
    }The keword "this" is still a problem for me. I start to belive im stupid or something.
Can you please explain what it does here? why not just write
InnerEvenIterator iterator = new InnerEvenIterator();Regards / Magnus

Answer 1

In the context of the example, this. is optional, but the authors were trying to emphasize that it's not simply a matter of creating an instance of any old class, so they explicitly used the this reference. The class reference is not always optional. If the printEven() method were defined as static, there would already have to be an instance of DataStructure such as ds created before the inner class could be instantiated:DataStructure ds = new DataStructure();
InnerEvenIterator iterator = ds.new InnerEvenIterator();