Static variables strange behavior in android

Question

i am facing a problem, very strange problem.

When i update any one static variable within a class then the other static variables in the class also got updated, don't know why this is happening.

please help me out, i don't even know what to do with this problem.

this line creating problem.

private static cSet currentSet = new cSet();
private static cSet currentPracticeSet = new cSet();
    public static void setCurrentPracticeSetRange(int from, int to)
{
    Log.e(currentPracticeSet.getCards().size()+" And "+currentSet.getCards().size(), to+" and "+from);
    getCurrentPracticeSet().getCards().clear();
    getCurrentPracticeSet().getCards().addAll(getCurrentSet().getCards().subList(from, to));

    Log.e("Range",currentSet.getCards().size()+"");
}

currentSet and CurrentPracticeSet are the private static member of class. Thanks,

That's better, but we still need to see your `static` variable declarations. — Robert Harvey, Apr 06 '13 at 18:50
Yeah, I don't know. If I were to guess I'd say you're setting `currentSet` to `currentPracticeSet` (or vice versa) somewhere in your code. If you do that, the two variables now *point to the same set.* — Robert Harvey, Apr 06 '13 at 19:00
@RobertHarvey why they are point to same set, set is just a class defined my me. — Ahmad Raza, Apr 06 '13 at 19:03

score 2 · Accepted Answer · edited May 23 '17 at 12:21

2

Static means that the scope of a variable is bounded by the class, not the object. If you change the value in one, they're all going to change.

Read here for more info.

edited May 23 '17 at 12:21

Community

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answered Apr 06 '13 at 18:43

`static` means that the variable is scoped to the class definition. It's not really an "instance," as such. – Robert Harvey Apr 06 '13 at 18:44
@RobertHarvey i know about static that why i am using them. but this is strange that you have 2 static variables in one class, when you change in one variable then the other variable got updated also. – Ahmad Raza Apr 06 '13 at 18:46
1

@AhmadRaza: Show us your code containing your variable declarations. My guess is you have an error in your code that is erroneously setting both variables. – Robert Harvey Apr 06 '13 at 18:46
@AhmadRaza: You still haven't shown us your static variables. We need to see those. – Robert Harvey Apr 06 '13 at 18:51

Static variables strange behavior in android

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