Static Variables

I'm working on an RPG, but I've hit a stumbling block - Static Variables. I searched in the Internet, but I'm not sure I understand completely.

Let's say I have a Quest Class, and from the Main Class, I create two Quest Objects:

Code:

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static Quest q, p;

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Now I have a Control class, and want to print out the quests' names:

Code:

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public class Control {
   
    public void controlPrint() {
        System.out.println("1: " + Main.q.getQuestName());
        System.out.println("2: " + Main.p.getQuestName());
    }
   
}

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If I don't make the Quest variables static, I can't access them. When I make them static, am I making the global? i.e. if I change their name from the Main, when I access them from the Control do I find their names changed?

Thanks a lot in advance.

Have you read the tutorial about variables explained here: Variables (The Java™ Tutorials > Learning the Java Language > Language Basics). And the other one on instance and class members here: http://docs.oracle.com/javase/tutori...classvars.html. If you haven't read it please take sometime to read it and ask for more if you still confuse about it.

Thanks for the links.

Quote:

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this tells the compiler that there is exactly one copy of this variable in existence, regardless of how many times the class has been instantiated.

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That cleared something, but I still don't understand everything.

Let's say I have the Quest Class and I create an instance of it; quest q. What does that change if I make that static?

Here is an snippet to test:

Code:

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class Test {
    static Quest quest = new Quest();
 
    public static void main(String[] args) {
        Test t1 = new Test1();
        Test t2 = new Test2();

        if (t1.quest == t2.quest) {
            System.out.println("t1.quest is t2.quest);
        }
    }
}

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From the example t1 and t2 is two different instance of Test. But as quest is declared static it become class variable, means it only exist as a single instance across all instance of the Test objects. So t1 and t2 will refer to the same quest.

Note, the example above is not a proper way to access static variable though. To access an static / class member you should always use something like Test.quest. This make our program clearer that quest is a static member of Test class.