Modifying an object's attributes by using another object's method

[skybluenova]

Hello all, I have a question that most of you will probably laugh about. But for my own purposes I am currently learning Java, and as I am quite new to programming and OOP, this problem actually arouse:

Given, I have two objects: Controller c1 and Bulb b1. This Controller object has a method called "setBulb", and it should be setting a "Bulb"'s attribute "isOn" to either true or false.

How do I accomplish that? I can't do this in the "Controller"'s method, as the object b1 has not yet been created and is therefore unknown ...

I hope this is not totally nonsense. I'd really appreciate any suggestions, and if what I want to do is totally bad programming style, I am glad if you'd correct me.

Best Regards
Dennis

[JosAH]

If a Controller needs to set a Bulb to on or off, it needs to have a Bulb; it can either create one or you can 'give' it one, otherwise the Controller doesn't have a Bulb and can't do anything ...

kind regards,

Jos

[skybluenova]

Thanks for the swift reply, Jos. So I thought, but lets say there are about 30 Bulb objects that need to be handed over ... how do I put them in an array?

Best
Dennis

[JosAH]

Thanks for the swift reply, Jos. So I thought, but lets say there are about 30 Bulb objects that need to be handed over ... how do I put them in an array?

One by one? Better put them in an ArrayList<Bulb>; it anticpates for more or less Bulbs to be put in it. Possibly a Bulb can put itself in the ArrayList<Bulb> in it's constructor that accepts the ArrayList<Bulb> as a parameter ...

kind regards,

Jos