How to call non-static method from static?

Question

I tried to call non-static drawScore() method from static calldrawScore(), but I got the error "cannot find symbol constructor Game" on line Game draw = new Game(); in calldrawScore(). When I pass with mouse over that line it says "GameScreen (Game) in Game cannot be applied to ()".

To call a non-static method you need an instance of the class the method expect. If you have this, you can call it anywhere. — Peter Lawrey, Sep 10 '13 at 09:36
Remember in OOP static means its a Class method as no-static means its an Instance method. — enkor, Sep 10 '13 at 09:43
possible duplicate of [What is the reason behind "non-static method cannot be referenced from a static context"?](http://stackoverflow.com/questions/290884/what-is-the-reason-behind-non-static-method-cannot-be-referenced-from-a-static) — user207421, Sep 10 '13 at 09:44

score 2 · Answer 1 · answered Sep 10 '13 at 09:34

2

- Its rule of thumb that a static method can't access any non-static variable or methods.

- It is because static member belongs to the class where as non-static members belongs to the object, so as the static member tries to access a non-static member it won't be clear that which objects member is being accessed, so its prohibited in JAVA.

answered Sep 10 '13 at 09:34

nidhi

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You can access a non static method from static method by creating an instance in the static method. – Code Enthusiastic Sep 10 '13 at 09:45
@CodeEnthusiastic you are right about it, thats one way of defining a singleton principle, but as far as i know, there is no direct way of accessing a non-static member from a static member and was something i wanted the OP to know, but thanks for providing another angle to this answer. – nidhi Sep 10 '13 at 10:42

score 0 · Answer 2 · edited May 23 '17 at 12:28

0

Maybe if you can change "getScore(int x)" into:

public static int getScore(int x, GameScreen gs) {
        score = x;
        gs.drawScore();
        return score;
    }

and now you can call it in "GameScree" by

GameScreen.getScore(valueSome, yourObject);

Another way is to change all GameScreen into Singleton

edited May 23 '17 at 12:28

Community

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answered Sep 10 '13 at 09:31

Dariusz Mazur

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score 0 · Answer 3 · answered Sep 10 '13 at 09:35

0

Your class GameScreen constructor is taking Game class object as a parameter. You can either get the current Game instance and pass it as a argument or create a default constructor in your Gamescreen class.

answered Sep 10 '13 at 09:35

prijupaul

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Adam Stelmaszczyk · Answer 4 · 2013-09-10T09:42:59.067

0

To do GameScreen d = new GameScreen() you need to have 0-argument constructor for GameScreen. You don't have such constructor.

Anyway, your code looks preety bad, because you are creating new GameScreen in every calldrawScore()...

I think you need to read what's the difference between static and non-static methods. Then go back, design it and implement better.

edited Sep 10 '13 at 09:42

answered Sep 10 '13 at 09:37

Adam Stelmaszczyk

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How to call non-static method from static?

4 Answers4