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javaandroidvb.netsyntaxequivalent

What is [Android] Java's equivalent of VB.NET's Static Keyword?


Is there a Java equivalent - specifically on Android - for VB.NET's Static keyword? For those not familiar with VB.NET, take the following code snippet...

Sub MyFunc() 
    Static myvar As Integer = 0
    myvar += 1
End Sub 

The Static keyword makes it so myvar retains its value between subsequent calls to MyFunc.

So after each of three calls to MyFunc, myvar's value would be: 1, 2 and 3 .

How do you make a cross-call persistent variable within a method in Java? Can you?


Solution

  • No. Within a method, Java doesn't have something which can be remembered across various calls.

    if you want to persist a value across multiple calls of a method, you should store it as instance variable or class variable.

    Instance variables are different for each object/instance while class variables (or static variables) are same for all the objects of it's class.

    for example:

    class ABC
    {
        int instance_var; // instance variable
        static int static_var; // class variable
    }
    
    class ABC_Invoker
    {
        public static void main(string[] args)
        {
            ABC obj1 = new ABC();
            ABC obj2 = new ABC();
    
            obj1.instance_var = 10;
            obj2.instance_var = 20;
    
            ABC.static_var = 50; // See, you access static member by it's class name
    
            System.out.prinln(obj1.instance_var);
            System.out.prinln(obj2.instance_var);
            System.out.prinln(ABC.static_var);
            System.out.prinln(obj1.static_var); // Wrong way, but try it
            System.out.prinln(obj2.static_var); // Wrong way, but try it
        }
    }