Question

In C# I can declare a static var in a class. E.g : to count the create instances of class “foo”. Like so

class foo
{
    static int countFoo =0;

    public foo()
    {
        countFoo++;
    }
}

Now – for each foo created I can use a getFooCount method to know how many instances were created.
How do you do that in Java?
I tried to do the same and it doesn’t work.
Please explain why and how. Thanks!

Answer 1

No, you can do exactly the same and it will work. Sample code:

class Foo
{
    private static int count;

    Foo()
    {
        count++;
    }

    static void printCount()
    {
        System.out.println(count);
    }
}

public class Test
{
    public static void main(String[] args)
    {
        Foo.printCount(); // 0
        Foo foo1 = new Foo();
        Foo foo2 = new Foo();
        Foo.printCount(); // 2        
    }
}

(It would have helped if you’d shown what you’d tried…)