Java error: class, interface, or enum expected

Question

I need to know the output of this code. But it's not working. Maybe the code is wrong. I'm still learning how to use Java, and I tried fixing this for hours but still no luck.

Here is the code:

public class A 
{ 
    public A() 
    {
        System.out.println ("A");
    }
}
public class B extends A 
{
    public B() 
    {
        System.out.println ("B");
    }
}
public class C extends B 
{ 
    public C() 
    {
        System.out.println ("C");
    }
}

public static void main(String args[]) {

    A a = new A();  
    B b = new B();  
    C c = new C();  
}

Can anyone tell me what is wrong or missing in the code?

Solution 1

For example:

public class Example {

    public static void main(String...args) {
        new C();
    }

    public static class A {
        public A() {
            System.out.println("A");
        }
    }
    public static class B extends A {
        public B() {
            System.out.println("B");
        }
    }
    public static class C extends B {
        public C() {
            System.out.println("C");
        }
    }
}

Also note that this might not print what you would expect. It would actually print:

A
B
C

Why? Constructors are always chained to the super class.

Solution 2

Put your main method in a class.

Filename : DemoClass.java

class A 
{ 
    public A() 
    {
        System.out.println ("A");
    }
}
class B extends A 
{
    public B() 
    {
        System.out.println ("B");
    }
}
class C extends B 
{ 
    public C() 
    {
        System.out.println ("C");
    }
}

public class DemoClass {

   public static void main(String args[]) {

       A a = new A();  
       B b = new B();  
       C c = new C();  
   }
}

Another point here is, you can have only public class in a file, so your A B and C all class can't be public in same java file.

Your java file name must be same as public class name. i.e. here DemoClass is public class so file name will be DemoClass.java

Java doc for getting started : getting started with java