Java-Gaming.org    
Featured games (79)
games approved by the League of Dukes
Games in Showcase (476)
Games in Android Showcase (106)
games submitted by our members
Games in WIP (532)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  [SOLVED] (ZetCode Tutorial) someone explain this line please  (Read 488 times)
0 Members and 1 Guest are viewing this topic.
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

"It's not at all important to get it right the first time. It's vitally important to get it right the last time."
Offline HeroesGraveDev

JGO Kernel


Medals: 238
Projects: 11
Exp: 2 years


┬─┬ノ(ಠ_ಠノ)(╯°□°)╯︵ ┻━┻


« 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

"It's not at all important to get it right the first time. It's vitally important to get it right the last time."
Pages: [1]
  ignore  |  Print  
 
 
You cannot reply to this message, because it is very, very old.

 

Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

pw (16 views)
2014-07-24 01:59:36

Riven (16 views)
2014-07-23 21:16:32

Riven (14 views)
2014-07-23 21:07:15

Riven (16 views)
2014-07-23 20:56:16

ctomni231 (43 views)
2014-07-18 06:55:21

Zero Volt (40 views)
2014-07-17 23:47:54

danieldean (32 views)
2014-07-17 23:41:23

MustardPeter (36 views)
2014-07-16 23:30:00

Cero (51 views)
2014-07-16 00:42:17

Riven (50 views)
2014-07-14 18:02:53
HotSpot Options
by dleskov
2014-07-08 03:59:08

Java and Game Development Tutorials
by SwordsMiner
2014-06-14 00:58:24

Java and Game Development Tutorials
by SwordsMiner
2014-06-14 00:47:22

How do I start Java Game Development?
by ra4king
2014-05-17 11:13:37

HotSpot Options
by Roquen
2014-05-15 09:59:54

HotSpot Options
by Roquen
2014-05-06 15:03:10

Escape Analysis
by Roquen
2014-04-29 22:16:43

Experimental Toys
by Roquen
2014-04-28 13:24:22
java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!