Global variables

[nikkka]

What if i want to use non-static ("changeable") global variable (available for all classes in file) like such one (example from C++):

#include <iostream>
int globalVar =0;
int main() { ... } // can use globalVar
int f(int x) // also can use globalVar
               //... and so on...

How can I create/use such variable in Java?

[JosAH]

What if i want to use non-static ("changeable") global variable (available for all classes in file) like such one (example from C++):

#include <iostream>
int globalVar =0;
int main() { ... } // can use globalVar
int f(int x) // also can use globalVar
               //... and so on...

How can I create/use such variable in Java?

There are no global variables in Java; what comes nearest is this:

public class Globals {
   public static int globalVar= 0;
}

... or you could create a singleton Globals object that holds the globalVar (which is quite useless here)

kind regards,

Jos

[nikkka]

Thank you very much, I didn't know that STATIC variables are "changeable" :)

[JosAH]

Thank you very much, I didn't know that STATIC variables are "changeable" :)

Yes they are; it are the 'final' variables that are not assignable. Don't build your applications with the scenario I outlined; it would be bad design.

kind regards,

Jos

[ozzyman]

The thing about static/class variables is that once they are changed, new instances of objects in that class will hold the value of changed static value rather initial value.

[DarrylBurke]

No, instances of classes do not "hold' a static variable. Static variables belong to the class, not to any instance.

All instances of all classes -- any line of code that accesses a static variable of any class -- will always see the current value of that variable.

db

[Tolls]

Don't build your applications with the scenario I outlined; it would be bad design.

kind regards,

Jos

I would just like to reiterate this.