OOP: Swap Method

[fsx]

Which would be the best way to implement a swap method in OOP? Basically the method just swaps (some) values of the same object type

a.) objectB = objectA.Swap(ob jectB) [returns new B and modifies A]

-or-

b.) objectHelper.Sw ap(objectA, objectB) [passing each object by ref]

-or-

c.) ????

Don't worry about what's actually getting swapped, I'm really interested in the best OOP method (low coupling, etc).

[r035198x]

Which would be the best way to implement a swap method in OOP? Basically the method just swaps (some) values of the same object type

a.) objectB = objectA.Swap(ob jectB) [returns new B and modifies A]

-or-

b.) objectHelper.Sw ap(objectA, objectB) [passing each object by ref]

-or-

c.) ????

Don't worry about what's actually getting swapped, I'm really interested in the best OOP method (low coupling, etc).

The OOP way to do swap? That's a strange question.
Well what you should be using here is cloning, copy constructor or both.

[fsx]

Method B is the how I would code it if I was using a non-OOP language.

Method A looks like OOP to me, but then I'm not an expert - which is why I'm asking ;-)

[r035198x]

Method B is the how I would code it if I was using a non-OOP language.

Method A looks like OOP to me, but then I'm not an expert - which is why I'm asking ;-)

There's a bit more to OOP than just how a method call looks like.
Swap doesn't really sound right as an action that can an object can perform. However if you have a class called ObjectUtils then Swap is a nice place for it.
Having said that, remember that by default object references are passed by value. To Swap objects using a Swap method you'll need to pass by reference. Do consider having a look at cloning (Copying) and or creating objects using the copy constructor.

[fsx]

So is it common to have a lot utility classes? I was trying to avoid creating utility classes, but maybe I was being too strict and putting too much in the non-utility classes.

[r035198x]

So is it common to have a lot utility classes? ...

That's not what I meant at all.

[fsx]

Sorry, I'm not trying to be annoying!

I have a system that has Car objects and Driver objects. The Drivers "swap" Cars, so I wasn't sure if I should use:

carA.SwapDriver (carB) ["Stateful" method in the Car Class]
- or -
CarUtility.Swap Drivers(carA, carB) [Shared method in the CarUtility Class]
- or -
carA.SwapDriver (carA, carB) [Shared method in the Car Class]

As it's a new project I didn't want to make a bad design decision at the start!

Thanks!!!

[r035198x]

Sorry, I'm not trying to be annoying!

I have a system that has Car objects and Driver objects. The Drivers "swap" Cars, so I wasn't sure if I should use:

carA.SwapDriver (carB) ["Stateful" method in the Car Class]
- or -
CarUtility.Swap Drivers(carA, carB) [Shared method in the CarUtility Class]
- or -
carA.SwapDriver (carA, carB) [Shared method in the Car Class]

As it's a new project I didn't want to make a bad design decision at the start!

Thanks!!!

The Car is not the one that does the Swap action is it? It's the Driver who swaps cars. So driver.SwapCar( Car newCar) is the way to go here. That SwapCar method really belongs to the driver not to the car.

[fsx]

Thanks - that makes sense.

So is it common to have a stateful class (i.e. Driver) that also has some unstateful (shared) methods? It looks like an obvious place to store them rather than break them out into a seperate class full of shared methods.

[r035198x]

Thanks - that makes sense.

So is it common to have a stateful class (i.e. Driver) that also has some unstateful (shared) methods? It looks like an obvious place to store them rather than break them out into a seperate class full of shared methods.

Actually form your scenario, the SwapCar mathod should not be shared at all. The only objects that should be allowed to SwapCars is an object of type Driver. The method SwapCar should thus be in the Driver class and not be made static. No other objects should have access to the SwapCar action unless those objects are Drivers.