Java error: class, interface, or enum expected,

Question

import java.util.*;

class box
{
   int h,w,d;
}

void volume()
{
   System.out.println("Volume="+(w*h*d));
}

class boxdemo
{
   public static void main(String arg[])
   {
      box b1=new box();
      box b2=new box();
      b1.h=10;
      b1.w=20;
      b1.d=30;
      b2.h=20;
      b2.w=30;
      b2.d=40;
      b1.volume;
      b2.volume;
   }
}

What's wrong with the code? please send me the correct code. It shows two errors saying class,interface or enum expected.

Answer 1

All methods in Java (also called "functions" in some other languages) must be inside a class.

Because volume references members of box I therefore assume it is intended to belong to box.

class Box
{
    int h,w,d;

    void volume()
    {
        System.out.println("Volume="+(w*h*d));
    }
}

Notice that I also changed box to Box becauses classes in Java start with an uppercase letter by convention.

Furthermore, method calls in Java end with parentheses, even if they do not take arguments:

//       vv
b1.volume();
b2.volume();