inner class

[Enkita mody]

Can we instantiate inner class in static method of outer class as we do in instance method ?

Thanks

[Jelle Klap]

Give it a try!

[Enkita mody]

Jelle Klap wrote:Give it a try!

this reference of outer class doesn't available in static methods.Please, tell me.

[Jelle Klap]

But this is trivial to just try out and see for yourself.

public class Foo {
  public static Bar newBar() {
     return new Bar();  
  }

  public class Bar {
  }
}

Either it compiles, or it doesn't. If you don't understand why it does or does not compile, maybe we can help with that.

[Campbell Ritchie]

It’s all in the Java Tutorials.

[Enkita mody]

class MyOuter1 
{
	public static void method(){
		MyInner1 i=new MyInner1();
		i.innerMethod();
	}
	class MyInner1
	{
		public void innerMethod() 
		{
			System.out.println("Hello World!");
		}
	}
	
}

---------- Compile ----------
MyOuter1.java:4: error: non-static variable this cannot be referenced from a static context
MyInner1 i=new MyInner1();
^
1 error

Output completed (1 sec consumed) - Normal Termination


I tried, it is not working.Now how to instantiate inner class here ?

[Campbell Ritchie]

What did you find in the Java tutorials link?

[Enkita mody]

Campbell Ritchie wrote:What did you find in the Java tutorials link?

It was same as i mentioned above this reference doesn't available in static methods.

An instance of InnerClass can exist only within an instance of OuterClass..

[Steve Luke]

ankita modi. wrote:

Campbell Ritchie wrote:What did you find in the Java tutorials link?

It was same as i mentioned above this reference doesn't available in static methods.

An instance of InnerClass can exist only within an instance of OuterClass..

Great, you have your answer then. You originally asked:

ankita modi. wrote:Can we instantiate inner class in static method of outer class as we do in instance method ?

and through both trial and reference you know the answer.

[Enkita mody]

Steve Luke wrote:

ankita modi. wrote:

Campbell Ritchie wrote:What did you find in the Java tutorials link?

It was same as i mentioned above this reference doesn't available in static methods.

An instance of InnerClass can exist only within an instance of OuterClass..

Great, you have your answer then. You originally asked:

ankita modi. wrote:Can we instantiate inner class in static method of outer class as we do in instance method ?

and through both trial and reference you know the answer.

No,that is not answer of my question.There could be a good answer of my question.Anyways i do post here

//inner class instantiate in static method of outer class
MyOuter.MyInner obj=new MyOuter().new MyInner();

-hth

[Campbell Ritchie]

That looks more promising. Now try that in a static method of the outer class.

[Enkita mody]

Campbell Ritchie wrote:That looks more promising. Now try that in a static method of the outer class.

class MyOuter 
{
	public static void myMethod(){
	       MyOuter.MyInner obj=new MyOuter().new MyInner();	
	       obj.demo();
	}
	class MyInner{
		void demo(){
			System.out.println("from inner");
		}
	}
	public static void main(String[] args) 
	{
		myMethod();
	}
}

---------- Run ----------
from inner

Output completed (0 sec consumed) - Normal Termination

[Campbell Ritchie]

Success!