How to extend inner class

[Subhash Pavuskar]

Hello Everyone !!

Can anyone please explain is that possible to extend inner class if yes then please give me the snippet of code.

Thanks

[Campbell Ritchie]

That question is vague. Is it a private or public inner class? Do you want to extend it inside the class or in another class? Why would you want to? What have ou tried so far?

[Abhijit Durge]

Hello, please see if the code snippet helps

public class Parent {

	public Parent() {
		super();
	}

	protected class Inner {

		public Inner() {
			super();
		}

	}

}

class Child extends Parent {
	class InnerExtended extends Parent.Inner{

	}
}

PS: InnerExtended needs to be inside a class extending Parent. In this case Child.

[Henry Wong]

Abhijit Durge wrote:
PS: InnerExtended needs to be inside a class extending Parent. In this case Child.

And if you don't want the outer classes to have any relationship whatsoever -- except for the inner class inheriting from each other that is -- then you can do something like this...

	public class A {
		public class InnerA {
			public InnerA(int i){
				
			}
		}
	}
	
	public class B {
		public class InnerB extends A.InnerA {
			public InnerB (A a) {
				a.super(3);
			}
		}
	}
	
	public class C {
		public class InnerC extends B.InnerB {
			public InnerC (B b, A a) {
				b.super(a);
			}
		}
	}

[EDIT] Just realized that the OP didn't mention that the inner class has to be extended by another inner inner class. Extending the inner class from a top level class is similar...

	public class B extends A.InnerA {
		public B (A a) {
			a.super(3);
		}
	}

Hope this helps,
Henry

[Winston Gutkowski]

Abhijit Durge wrote:PS: InnerExtended needs to be inside a class extending Parent. In this case Child.

I see nothing wrong with what you've written (apart from maybe your names). However, to make Inner extendable by ANY class that extends Parent, you should really make it protected, viz:
protected class Inner { ...

However, my question would be: How often do you think you're going to need this information? True inner classes are rare enough, and their use tends to suggest finality, not extension. If it's for the SCJP exam, then good luck with that; but the chances of you ever needing to use it in real life are slim to none (in eleven years of Java programming, I haven't).

Winston

[Kemal Sokolovic]

Abhijit Durge please UseCodeTags and format your code accordingly.