On Sat, Sep 27, 2008 at 1:40 PM, Andy Burnett <[EMAIL PROTECTED]> wrote: > I read somewhere - can't remember where - that setters are considered evil. > The argument was that in the real world you can't suddenly change the colour > of a car, just by settings its colour value. Instead, you have to perform > some action, e.g. sprayPaintCar: aColour. Therefore in the OO world, one > should tackle problems in the same way, i.e. if you want to change the value > of an instance variable, you have to call some sort of action method, that > makes sense in the context of the object.
This is not a good argument. Many Smalltalk objects are not modeled after the real world. Even if they are, is there really any difference between sprayPaint: aColour and colour: aColour? Setters are neither good nor evil. It is how you use them that is good or evil. Many people overuse setters. I try to avoid setters because it is harder to tell where a variable is modified if there is a setter. But sometimes they are just what you need. -Ralph Johnson _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners
