Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
564 views
in Technique[技术] by (71.8m points)

static - problem creating object of inner class in java


Here is the code.

public class Test {
        class InnerClass{

               }

   public static void main(String[] args){
            InnerClass ic = new InnerClass();
        }
    }

It says the error message

non-static variable this cannot be referenced from a static context
after creation of object ic.

Can anyone give me the reason?

Thanks

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

InnerClass needs to be static itself, i.e.

public class Test {

   static class InnerClass{    
   }

   public static void main(String[] args){
      InnerClass ic = new InnerClass();
   }
}

If InnerClass is not static, it can only be instantiated in the context of a parent instance of Test. The rather baroque syntax for this is:

public class Test {

   class InnerClass{    
   }

   public static void main(String[] args){
      Test test = new Test();
      InnerClass ic = test.new InnerClass();
   }
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...