aspose file tools*
The moose likes Beginning Java and the fly likes Weird error not sure what Im doing wrong Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login
JavaRanch » Java Forums » Java » Beginning Java
Bookmark "Weird error not sure what Im doing wrong" Watch "Weird error not sure what Im doing wrong" New topic
Author

Weird error not sure what Im doing wrong

Keshan Pillay
Greenhorn

Joined: May 21, 2008
Posts: 29
Hi everyone! I'm doing an assignment for university (compsci 101), where I have to program a simple 2d game. So I chose brick, (the one with the ball and the paddle) and I've gotten this far.



What I'm trying to do here is to make the 3 arrays row1OfBricks, row2OfBricks and row3Ofbricks, then I want to draw the rectangles stored in these arrays in the paintComponent method. The arrays are initialized correctly, and the values they all store are all correct. But when I try an use something like row1OfBricks[1].x in the paintcomponent method, to access the x value of the rectangle in position 1 of the array, I get this mega error that streams down the console and doesn't stop.
When I try and access row1OfBricks[1].x anywhere else, it returns the correct value.
But in the paintcomponent method ive put in
System.out.println(row1OfBricks[1].x);
just as a test, and it errors.

Any help would be appreciated.
Joanne Neal
Rancher

Joined: Aug 05, 2005
Posts: 3580
    
  15
You've got row1OfBricks defined twice - once as an instance variable and once as a local variable in the GUIJPanel constuctor, so the constructor will initialise the local variable, but the paintComponent method will use the instance variable that has not been initialised.


Joanne
Keshan Pillay
Greenhorn

Joined: May 21, 2008
Posts: 29
omg wow, thanks so much! I feel stupid for not catching that myself.
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 38910
    
  23
And welcome to JavaRanch.

It takes quite a lot of experience to pick up that sort of mistake.
Keshan Pillay
Greenhorn

Joined: May 21, 2008
Posts: 29
Thank you very much for the kind welcome, I'm sure I'll be spending a lot of time here ^^
 
wood burning stoves
 
subject: Weird error not sure what Im doing wrong