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  [SOLVED] (ZetCode Tutorial) someone explain this line please  (Read 436 times)
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Offline alaslipknot
« Posted 2013-04-20 04:36:44 »

Hello,
am following this tutorial
http://zetcode.com/tutorials/javagamestutorial/collision/
and i didn't understand the need of this line in the Board class
(ctrl+f to find it easily )

1  
Missile m = (Missile) ms.get(i);

and this
1  
Alien a = (Alien) aliens.get(i);


i know that the variables "m" and "a" are the temporary missile and alien inside the loops, but why the casting ?
(Missile) ms.get(i) ??

i really don't know why i had to cast

thank you

Am trying ...
hoping that it works
Online HeroesGraveDev

JGO Kernel


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If it wasn't Awesome, it wasn't me.


« Reply #1 - Posted 2013-04-20 04:41:37 »

When defining the ArrayList, they don't use generics, so the compiler doesn't know what type the objects pulled out of the arraylist will be.

To avoid casting, define the ArrayList like this:

1  
ArrayList<Missile> missiles = new ArrayList<Missile>();


etc.

Offline alaslipknot
« Reply #2 - Posted 2013-04-20 05:37:19 »

Thank you  Grin

Am trying ...
hoping that it works
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