Putting data into array

[Arthur Donting]

hey guys, I need to create an array of classes. for now i have this fragment:

public class Test {


	public static void main(String[] args) {

		CarData[] auto = new CarData[15];
		
		auto[0].brand="Fiat";
		auto[0].fuel='D';
		auto[0].consumption=7.9;
		auto[0].release=1998;
		auto[0].antiBlock=false;
	}
}
class CarData {
    public String brand;
    public char fuel;
    public double consumption;
    public int release;
    public boolean antiBlock;
}

I keep getting NullPointerException. When i use this:

public class Test {


	public static void main(String[] args) {

		CarData auto = new CarData();
		
		auto.brand="Fiat";
		auto.fuel='D';
		auto.consumption=7.9;
		auto.release=1998;
		auto.antiBlock=false;
	}
}
class CarData {
    public String brand;
    public char fuel;
    public double consumption;
    public int release;
    public boolean antiBlock;
}

everything works just fine but i need to have an array. Coud anyone help out with this?

[Campbell Ritchie]

Have you really been given a CarData class with public fields like that? Very bad design.

Have you initialised the array to anything before trying to gain access to its 1st element? If not, you will suffer a NullPointerException.

[Sebastian Janisch]

Thats becaus you have to initialize your array indexes with Cars.

array[0] = new CarData();
array[0].name = "";

As a little advice, try not to access properties directly. Encapsulate them by using JavaBean Properties.

[Campbell Ritchie]

Have you initialised the 1st element in the array to anything? If not you will suffer a NullPointerException there too.

Remember if you declare anything, that doesn't have any value until you initialise it. If you have a 15-member array, then you have 15 references which all point to null until you tell them otherwise.

[Arthur Donting]

solved everything. thanks a lot guys

[Campbell Ritchie]

You're welcome