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Headfirst Fullmoons exercise

Alberto Fontova
Greenhorn

Joined: Oct 26, 2007
Posts: 2
Hi, I've been working through the headfirst book and really liking it & finding Java to be very cool!!

I think i missed something fundamental though about static variable.

I solved this exercise & got the program to compile & run fine.

Code-

import java.util.*;

import static java.lang.System.out;

class FullMoons {

static int DAY_IM = 1000*60*60*24;

public static void main (String [] args) {
Calendar c= Calendar.getInstance();

c.set(2004,0,7,15,40);

long day1 = c.getTimeInMillis();

for (int x=0; x<60;x++) {
day1+= (DAY_IM *29.52);

c.setTimeInMillis(day1);

out.println(String.format("full moon on %tc",c));
}

}
}

Then i started messing around and tried to create a class I could call in main along with some other stuff just for fun.

code-

class FullMoons {

static int DAY_IM = 1000*60*60*24;

public static void main (String [] args) {
Calendar c= Calendar.getInstance();

c.set(2004,0,7,15,40);

long day1 = c.getTimeInMillis();

for (int x=0; x<60;x++) {
day1+= (DAY_IM *29.52);

c.setTimeInMillis(day1);

out.println(String.format("full moon on %tc",c));
}

}
}

This won't compile. When I take DAY_IM out it will compile. I think it has something to do with DAY_IM being static but I don't know the why.

Thanks for the help.
Rob Spoor
Sheriff

Joined: Oct 27, 2005
Posts: 19720
    
  20

"day1+= (DAY_IM *29.52);"

The result of (DAY_IM * 29.52) is a double, not a long. If you cast this back to a long it should work.


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amit punekar
Ranch Hand

Joined: May 14, 2004
Posts: 514
Hello,
What is the compilation error you are getting?
I compiled and ran the program you posted successfully.

regards,
amit


Regards,
Amit
Alberto Fontova
Greenhorn

Joined: Oct 26, 2007
Posts: 2
Can't believe I missed that! Thanks for the help.

Amit, message from the compiler was something like "...expected". It's working now. Thanks for the reply.
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: Headfirst Fullmoons exercise