box2d not running

damaru

in Contributed Library Questions • 2 years ago

Hi all,

as soon as I have ArrayList<particle> particles; in my code processing stop and give me an "unexpected token void", of course if I comment out ArrayList<particle> particles; it spits out an error later on in the code (because the arraylist is not initialized)

Would it be my version of processing or java that is not happy ? It seems to be an obvious oversight of mine but I can't figured it out.

I am on ubuntu 9.10 ~ 64bit

thanks

Replies(6)

PhiLho

Re: box2d not running

2 years ago

" Would it be my version of processing or java that is not happy ?"
Perhaps, but we can't guess them...
Or you just have a syntax error, but we can't guess the syntax you use...

damaru

Re: box2d not running

2 years ago

heheh indeed ~ sorry for not giving more info about this.

Well I am just using the examples from box2d - any of the examples that has ArrayList<Box> boxes; for example the applyforce example that come with the libraries. On processing 1.0.9 .... and ho... yes it was an because I am using an older version :S

(I wish I could have an imaginary forum where I can post question and answer them myself without having to look dumb to the whole communnity each time :)

gef

PhiLho

Re: box2d not running

2 years ago

I don't recall exactly when Processing adopted the Java 1.5 syntax (the <> syntax) but I am pretty sure that 1.0.9 doesn't support it. Either upgrade or use the "good" old syntax without generics.

damaru

Re: box2d not running

2 years ago

yeah it was my feeling that the <> where in a newer java version language - what are generics btw ?

shiffman

Re: box2d not running

2 years ago

Hi all!

So I've started using Generics in my examples b/c I am a sucker for the "enhanced" for loop.

for (Particle p : particles) {

p.go();

}

It's so lovely!

But I've found its confusing people a bit. I added a section in chapter 4 of the nature of code book which covers generics, but I will try to post a tutorial online somewhere, likely on my blog and/or the Processing wiki. Someone remind me if you don't see something soon!

Java has more info here:

http://download.oracle.com/javase/tutorial/java/generics/index.html

but this is about designing generics also where most processing users will just want to use them in the context of ArrayLists, etc.

Dan

damaru

Re: box2d not running

2 years ago

I agree with these loop for managing array are quite good - I learned it in Java but never tough of using it in processin (like the arraylist too)

thanks for the link on generic!

Top Reply