How to call an inner class method from static main () method

Question

Trying to create 1 interface and 2 specific classes inside the parent class. This will qualify the included classes as inner classes.

public class Test2 { interface A{ public void call(); } class B implements A{ public void call(){ System.out.println("inside class B"); } } class C extends B implements A{ public void call(){ super.call(); } } public static void main(String[] args) { A a = new C(); a.call(); } } 

Now I'm not sure how to create an object of class C inside the static main () method and call the method to call class C (). Right now I am getting problems in the line: A a = new C();

Answer 1

Here, the inner class is not static, so you need to instantiate the outer class, and then call a new one,

 A a = new Test2().new C(); 

But in this case, you can make the inner class static,

 static class C extends B implements A 

then it's ok to use

 A a = new C() 

Answer 2

To create an instance of an inner class, you must first create an instance of the outer class. Then create an internal object inside the external object using this syntax:

 OuterClass.InnerClass innerObject = outerObject.new InnerClass(); 

So you need to use:

 A a = new Test2().new C(); 

Refer to the Java Tutorial .

Answer 3

You have to do it

  A a = new Test2().new C();