Add an object to an Array of a custom class

Question

Im a beginner to Java and I'm trying to create an array of a custom class. Let say I have a class called car and I want to create an array of cars called Garage. How can I add each car to the garage? This is what I've got:

car redCar = new Car("Red");
car Garage [] = new Car [100];
Garage[0] = redCar;

Naming conventions: variables start with lower case and objects with upper case: `Car redCar = ...`, `Car[] garage = ...`, `garage[0]` etc. — assylias, May 01 '12 at 16:00

score 27 · Accepted Answer · answered May 01 '12 at 15:59

27

If you want to use an array, you have to keep a counter which contains the number of cars in the garage. Better use an ArrayList instead of array:

List<Car> garage = new ArrayList<Car>();
garage.add(redCar);

answered May 01 '12 at 15:59

Petar Minchev

45,963
11
102
118

1

And how can I get a particular car in the garage? Like how do I get the first car added? – Dangerosking May 01 '12 at 16:01
+1 for the list suggestion :). The next step would be to implement `equals()` and `hashCode()` and use a `Set` (since it might not make much sense for exactly the same car to be in a garage twice :) ). – Thomas May 01 '12 at 16:01
@Dangerosking - Use `garage.get(0)` – Petar Minchev May 01 '12 at 16:02
*"And how can I get a particular car in the garage?"* http://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html – CodeClown42 May 01 '12 at 16:03
Can the arraylist be used in a abstract class? Just like the array, I can create it but I can't add an object to it. – Dangerosking May 01 '12 at 18:24
nvm I got it to work, thanks :) – Dangerosking May 01 '12 at 19:35

score 11 · Answer 2 · answered May 01 '12 at 16:00

11

The array declaration should be:

Car[] garage = new Car[100];

You can also just assign directly:

garage[1] = new Car("Blue");

answered May 01 '12 at 16:00

CodeClown42

10,872
1
30
63

Pat Murray · Answer 3 · 2012-05-01T16:06:38.873

6

If you want to create a garage and fill it up with new cars that can be accessed later, use this code:

for (int i = 0; i < garage.length; i++)
     garage[i] = new Car("argument");

Also, the cars are later accessed using:

garage[0];
garage[1];
garage[2];
etc.

edited May 01 '12 at 16:06

answered May 01 '12 at 16:01

Pat Murray

3,825
6
25
32

Add an object to an Array of a custom class

3 Answers3

Linked