SRL Archive - Java Help and Tutorials

well i just started learning java again and i forgot nearly everything

anyway so far i have this

class First {
    int x = 2;
}

public class Main {

    public static void main(String[] args)
    {
        First[] testing = new First[5];
        
        testing[2].x = 5;
        
        System.out.println(testing[2].x);
    }
}

it compiles fine but when i run it i get

Exception in thread "main" java.lang.NullPointerException
at Main.main(Main.java:11)

any ideas are welcome

~shut

change to this.

class First {
    int x = 2;
}

public class Main {

    public static void main(String[] args)
    {
        First[] testing = new First[5];
        testing[2] = new First();
        testing[2].x = 5;
        
        System.out.println(testing[2].x);
    }
}

From: Yakman
change to this.

class First {
    int x = 2;
}

public class Main {

    public static void main(String[] args)
    {
        First[] testing = new First[5];
        testing[2] = new First();
        testing[2].x = 5;
        
        System.out.println(testing[2].x);
    }
}

hmmm… ok, thanks :)

so if i was to create a array that had a length of 1000, then i would have to do that for each one?

if i do then i know i could obviously just use a loop

~shut

You should create a constructor for your inner class and using that constructor initialize your array. It is much simpler.