Java array of objects

Question

I created a class Car. It includes a location, a double array size 2. I'm trying to create an array of Cars. Here is what I have:

Car[] cars;
cars = new Car[3];

cars[0].location = new double[]{1,6};
cars[1].location = new double[]{10,30};
cars[2].location = new double[]{20,7};

I get an error where I try to declare the location: NullPointerException. How do I resolve this?

You haven't initialized the elements in the array.

Sotirios Delimanolis
– Sotirios Delimanolis

2014-02-02 02:07:41 +00:00
Commented Feb 2, 2014 at 2:07 — Sotirios Delimanolis
– Sotirios Delimanolis, Commented Feb 2, 2014 at 2:07

sma · Accepted Answer · 2014-02-02 02:09:50Z

4

You need to create reference variables for the objects in the array. Your original code simply initializes a Cars array of size 3, but doesn't put any objects inside.

Car[] cars;
cars = new Cars[3];

for (int i=0; i<3; i+=1) {
    cars[i] = new Car();
}

cars[0].location = new double[]{1,6};
cars[1].location = new double[]{10,30};    
cars[2].location = new double[]{20,7};

answered Feb 2, 2014 at 2:09

sma

9,5978 gold badges53 silver badges83 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Java array of objects

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related