GeekWatch- error: static reference

[yen cheong]

Hiya again
I am stuck on GeekWatch- when trying to work out the no. of Milliseconds since Jan 1 1970. I have created an instance of the class Date and assigned this to variable date. I then try to initialise a variable , noOfMilliSecs (of type public long) using a method within the Date class with the following syntax:
I'm sorry but I had to remove the actual code
However I get the following message when I try and compile:
GeekWatch.java:45: Can't make a static reference to nonstatic variable noOfMilliSecs in class GeekWatch
Please can you help
Thanks
Yen

[This message has been edited by Johannes de Jong (edited August 20, 2001).]

[Johannes de Jong]

I suggest you look at Thread1 & Thread2
Hope that helps

[yen cheong]

Johannes
Thank you for your replies so far to all my Qs. I have read Thread 1 and Thread 2, but am confused. In my code, I have created an instance of the Date object, before running the ***() method (which is non-static) inside main. So I don't understand why I am getting this error message??!! Is there something that I am missing here?
Thanks in advance
Yen
Sorry I had to remove the name of the method. Part of the assignment is finding/using the correct method
[This message has been edited by Johannes de Jong (edited August 20, 2001).]

[Johannes de Jong]

Have you got your "call" to the method in this format : long xxx = object.method() ?

[yen cheong]

Johannes
Wow ......... how did that work??!! Originally I had long xxx;
declared in the class but outside main, but it caused the error message!! I have now called the method as advised, and it doesn't cause a compilation error.
??? Please can you explain.
Regards
Yen-yei

[yen cheong]

I tried declaring as both:
public long xxx;
and
private long xxx;
and they both still caused the compilation error

[jason adam]

Because main() is static, you can't directly access any non-static variables initialized outside of main() (instance variables)unless you have an instance of your class, same thing goes for non-static methods.
Ways to correct this is:
1) Make your instance variables class variables by declaring them static (probably want to declare them private, also).
2) Instantiate an object of your class. This will allow you access the instance variables in main() via object.variable. For instance:

public class MyClass
{
    int i ;
    public static void main( String[] args )
    {
        MyClass mc = new MyClass() ;
        mc.i = 0 ;
     }
}

Hope this helps some,
Jason
[This message has been edited by jason adam (edited August 20, 2001).]
[This message has been edited by jason adam (edited August 20, 2001).]

[yen cheong]

Hi Jason
Thanks for your reply, however I am still confused as I had already created an instance of the class inside of main. I had to declare the variable inside main to prevent the compilation error.
Regards
Yen

[yen cheong]

Hi
Sorry I think I understand this now.
Regards
Yen

[Michael Matola]

One note on Jason's example -- it won't compile as is. You can't use "this" inside a static method.

[jason adam]

My bad Michael, yer absolutely correct about that. Been writing too many constructors lately and got all discombobulated.
Thanks!
Jason