Objects

[maths94]

Hypothetically speaking if i had multiple objects all being drinks e.g. coke, fanta and sprite. I then wanted a new object that is a drink, but is a combination of coke, fanta and sprite ( in a new class ). How could i do this ? would this be possible ?

[maths94]

Thanks a lot. Do you mind if i send you a pm with my current code, because the structure is extremely distinctive; and it's quite difficult trying to follow this with my structure. Since it's a project, i'm unable to post my code online: ( . If not, then thanks anyway, much appreciated, i'll just try get it working utilizing your advice.

[ChristopherLowe]

Edit
I messed up and deleted my message.. Here is what I wrote one post up.


Absolutely, this kind of thing is fundamental Object Orientated programming. Polymorphism allows you to define something that represents many types. The basic concept is to define an interface, which we will call 'IDrink'. Then create concrete implementations 'Coke' and 'Sprite'.

public interface IDrink {
    public void drink();
}

public class Sprite implements IDrink {
    public void drink() {
        System.out.println("The thirst quencher.");
    }
}

This kind of approach is very flexible because it allows you to define the properties (nouns) and methods (verbs, doing words) of a entire category of objects. Additionally it allows you to treat all of these objects in the same manner. We could easily create a 'VendingMachine' class with an array of 'IDrinks' that dispenses drinks to a 'ThirstyConsumer' who will no doubt enjoy the beverage.

Adding or changing drinks has been separated from the users by a contract so it's exceptionally easy to add or modify drinks.

[KevinWorkman]

Are you talking about a drink that is a mix of multiple other drinks? In that case you could have some kind of data structure that holds the composite drinks in a new class that extends Drink.

But do all of these drinks have a different behavior? Or do they just have different names and attributes? In the latter is the case, then you might want to favor composition over inheritance here and just have a single Drink class that you instantiate multiple times with different attributes.

[ChristopherLowe]

Thanks a lot. Do you mind if i send you a pm with my current code, because the structure is extremely distinctive; and it's quite difficult trying to follow this with my structure. Since it's a project, i'm unable to post my code online: ( . If not, then thanks anyway, much appreciated, i'll just try get it working utilizing your advice.

Design questions are very hard to answer because if they are made incorrectly you either need to refactor or re-write. I simply do not have the time to review an existing code base for design flaws and those that can won't (shouldn't) do it for free. Without an SSCCE we cannot advise you on what is wrong with your code only that is seems like Polymorphism (many forms) seems like a good solution to your generalized problem.

[maths94]

Design questions are very hard to answer because if they are made incorrectly you either need to refactor or re-write. I simply do not have the time to review an existing code base for design flaws and those that can won't (shouldn't) do it for free. Without an SSCCE we cannot advise you on what is wrong with your code only that is seems like Polymorphism (many forms) seems like a good solution to your generalized problem.

Someone suggested a hashMap, could this work?

[Norm]

is a combination of coke, fanta and sprite

What drink is a combination of those 3 drinks?
Is that a completely new drink with those 3 flavors mixed together
or is there some kind of dispenser that allows a user to get any one of those 3 drinks?
Before writing any code (HashMap) you need to decide on what the new class is.

[GregBrannon]

Or separate the "Drink" (or Beverage?) from the contents. The parent class for the contents may be may be Soda with child classes Coke, Pepsi, Sprite (never in the same establishment), Root Beer, SevenUp, MountainDew, etc. Ultimately, the customer is buying a Drink or Beverage that could be a certain sized cup filled with a single flavor or multiple flavors. It's the customer's Drink or Beverage the specifies what's in it.

[maths94]

What drink is a combination of those 3 drinks?
Is that a completely new drink with those 3 flavors mixed together
or is there some kind of dispenser that allows a user to get any one of those 3 drinks?
Before writing any code (HashMap) you need to decide on what the new class is.

Basically, it's a pizza, Pre-defined Pizza e.g. margarita so i've got topping objects, base ect but i need to somehow combine them to make a 'predefined' pizza

[GregBrannon]

Pizza? I thought we were talking about sodas. Don't talk in riddles.