如何将类实例化为变量名？

Question

I am working on an assignment, and I have hit one roadblock. I am simply calling a string array from another class. The code in the other class (named ProductDB) is this:

public String[] inventory =  {"java", "jsps", "mcb2", "txtp"};

And in the main application class (named ProductApp) I have this code:

public static void showCodes()
{
    System.out.print("  Select from");
    System.out.print("  =>  ");
    for (String show : productDB.inventory)
    {
        System.out.print(show.toUpperCase() + " ");
    }
    System.out.print("  <=");
}

The error I am getting with productDB is 'Cannot find symbol' (I am using NetBeans).

I need to instantiate a variable named productDB correct? How do I do this within the ProductApp class level?

Answer 1

You can set inventory to static , which makes it possible to call it in other classes by ProductDB.inventory .

If you want to use it as you are now, with an instance of ProductDB, simply create an instance variable in class ProductApp (which must be static, since your method is static).

static ProductDB productDB = new ProductDB();

Answer 2

如果您的productDB是一个类，则需要将inventory成员声明为static 。