NullPointerException error

[Aggror]

Hello,

I have 2 classes: Point and Hook. The Point class has 2 fields: x and y.
In the Hook class I can create an array of Points. However I get a NullPointerException error when assigning a value to this x value via the Hook class.

here is the Point class:

public class point{
        int x;
        int y;

        //default constructor
        point(){
            x = 0;
            y = 0;
        }

here is the hook class:

public class Hook{
        //declare array
        point array1[];

        //make the default constructor
        Hook(){
            //make a new array existing out of points from the point class.
            array1 = new point [3];
            array1[0].x = 90;

        }

This line "array1[0].x = 90;" gives me the exception error.

According to this exception 'array1[0].x ' does not exist. Can someone explain to me what is going wrong here?

[masijade]

An array declaration creates an array of references, but, until you assign a value to these references, they all point to null. You need to add an array1[index] = new point(); before you start assigning the x and y values at that index.

[Aggror]

Ah, so obvious now that you explained it to me. Thank you very much for a quick and accurate response