How to call method in inner class using java?

Question

Can you call method in inner class without calling constructor in class A this my code:

public class A {

    public A() {
        System.out.println("You are in Class A");
    }

    public class innerA {

        public innerA() {
            System.out.println("You Are in Class InnerA");
        }

        public void PrintName() {
            System.out.println("Jack in InnerA");
        }
    }
}

public class B {
    A.innerA obj = new A().new innerA();
}

No you can’t, by definition an inner class needs an instance of an outer class and creating an instance always invokes the constructor. [barring esoteric cases like deserialization and cloning] — Erwin Bolwidt, Sep 07 '18 at 09:42
An inner class is part of the instance, a static nested class is just part of the class. This is the same as a member, you can't access a variable without creating an instance first. — AxelH, Sep 07 '18 at 09:45
Possible duplicate of [Java inner class and static nested class](https://stackoverflow.com/questions/70324/java-inner-class-and-static-nested-class) — AxelH, Sep 07 '18 at 09:46

score 4 · Accepted Answer · answered Sep 07 '18 at 09:40

4

Well you need an instance of InnerA to actually call a method on it and in your case you can't do that because you would also need an instance of A for that.

You could change the declaration to:

static public class InnerA {...}

thus not needing an instance of A, only an instance of InnerA

answered Sep 07 '18 at 09:40

Eugene

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Hey did you also think about making InnerA and the wanted method static? – Casper Sep 07 '18 at 09:44
But it would no longer be an inner class (it would be a static member class) – Erwin Bolwidt Sep 07 '18 at 09:45
@ErwinBolwidt ah, I didin't know there was a diffrence :) – Casper Sep 07 '18 at 09:47

score 0 · Answer 2 · answered Sep 07 '18 at 10:11

    class Car { 
       void carMethod() { 

          System.out.println("inside carMethod"); 
          class TataCar { 
             void tataCarMethod() { 
                System.out.println("inside tataCarMethod"); 
             } 
          } 
          TataCar y = new TataCar(); 
          y.tataCarMethod(); 
       } 
    } 
    class MainClass { 
       public static void main(String[] args) { 
          Car carObj=new Car(); 
          carObj.carMethod(); 
       } 
    }


    Output:
    inside carMethod
    inside tataCarMethod

How to call method in inner class using java?

2 Answers2