   How to avoid getters and setters?
  So I made this classclass AnimSetter{    int state;    int facing;    bool changed;    public:    AnimSetter(int state, int facing): state(state), facing(facing), changed(true) {}    void SetState(int newstate) {if (newstate != state) {changed = true; state = newstate;}}    void SetFacing(int newfacing) {if (newfacing != facing) {changed = true; facing = newfacing;}}    int State() const {return state;}    int Facing() const {return facing;}    bool Changed() {bool temp = changed; changed = false; return temp;}};Getters and setters are usually frowned upon, but I can't think of anyway to rewrite this code to get rid of them. It is basically a struct, but I need some way of logging all changes so that I can tell whether it has been changed since the last call.   
  Really? I always thought the general consensious is they are A Good Thing. I certainly think they are, and infact for exactly the reason you're using here.Checking if the variable is different to it's previous value to avoid unnecessary work, and also allowing you to do extra checks or work in the get/set at some future time, without having to modify the rest of your code.There are those that will argue about the performance of a function call vs setting the value directly, but meh, in most cases this will be negligible.;Quote:Original post by StoryyellerSo I made this class*** Source Snippet Removed ***Getters and setters are usually frowned upon, but I can't think of anyway to rewrite this code to get rid of them. It is basically a struct, but I need some way of logging all changes so that I can tell whether it has been changed since the last call.make the variables public then. Or just deal with the fact that you'll need them to allow access to variables you've made private but still want outsiders to use.   ;  You can get away with just using a simple struct if you change the way you're detecting state changes. Instead of using a dirty flag, you could use comparisons:struct AnimSetter{    int state;    int facing;    bool operator==( const AnimSetter& last ) const    {  return state==last.state && facing==last.facing; }    bool operator!=( const AnimSetter& last ) const    { return !(*this == last); }};bool Changed( const AnimSetter& now, const AnimSetter& earlier ) const { return now != earlier; }This design does increase your storage costs, but it also reduces the amount of branching required (no pipeline flushing required inside a setter). If you have huge structs, then the flag-based method is probably more optimal, otherwise, for small structs like this (8 bytes!) I'd go with duplication/comparison.Quote:Original post by supamikeReally? I always thought the general consensious is they are A Good Thing. I certainly think they are, and infact for exactly the reason you're using here.Having a class that exposes all of it's members via setters/getters is a sign of a bad design, as it shows the class isn't taking on any responsabilities other than data storage/validation. In Storyyeller's example, this is exactly the case so I wouldn't fault his original design, but if they keep showing up in other areas it can be a bad sign -- usually most of a classes members should be internal, and hidden from the clients of the class.In other words, one objective of making members private is to hide them from the classes interface. If you then add setters/getters, you've re-added them to that interface/contract. You've succeeded in protecting the integrity of your objects, but failed in seperating interface from implementation.   ;Quote:Original post by StoryyellerGetters and setters are usually frowned upon, but I can't think of anyway to rewrite this code to get rid of them.You wont be able to by only considering that piece of code, and neither will we.OOP is the uniting of "code" and "data" into "objects". Using getters and setters often means that the data is in one class and the code that uses it is in another. You need to examine whether these variables really belong in this class, or whether they belong with the code that uses them. Or equally likely, you need to consider whether some of the code that deals with them should be in this class as well.You can show the code that uses these if you like.[smile]Finally, in a few cases, getters and setters can sometimes be a reasonable means to an end.   ;  The way of avoiding getters and setters is to move the functionality which needs them into the class itself, and expose it as more domain oriented requests.For example, take a font object. It has a fontname, a size, a colour and some flags to say whether it's underlined, bold, italic.You could implement this by having all the users call setters;myFont.setBold(true);myFont.setUnderline(false);myFont.setColour(0,0,0);myFont.setFont("wobbly.fnt");However this fails to be good style for two reasons. Firstly it transfer responsibility out of the class into the user who now needs to know how to setup fonts. Secondly it means that you are solidifying the interface -- if later on you add an "outline" flag there's no trivial way to make sure everyone is setting it correctly.So the way to do this is to make your font into a person to whom you send requests.myfont.setHeader();render(myfont,"Headings -- A Starting Point");myfont.setBody();render(myfont,"Lorem ipsum etc");And now you don't need individual setters.;  Depending on the language you're using, it might have some of that stuff built in (granted it looks like you're using C++).If you were being all fancy with XNA and C# you would be able to do:public int MyVariable { get; set;}   ;  Getters and setters aren't bad, they are good.Some reasons they are good:* They are a choke point of reading and writing your data which means you can put data validation (even if debug only validation) in them to find any cases you are getting bad data or to ensure you only store good data.* You can set breakpoints in them if you wonder when a variable is getting changed by your code.* You can change how it's stored without changing the interface.  ie if you have a GetPos and SetPos on a player, you could change how it's stored from a float array to a D3DXVECTOR3 perhaps, without having to change all the code that calls it.Reasons they are bad:* Getters / Setters add overhead by requiring a function call vs direct access of the data.  NOT TRUE, you can make them inline functions and then they are as fast as if you weren't using them.   ;  The only arguments I have seen on Get/Set is either extra verbiage, or just plain unsightliness.  Attributes should be protected from direct outside meddling, and depending on you level of OOP purity you have different ways to doing that.  My rules of thumb on "good code" is:1) Does it work and do what it is expected to do.2) Can someone else look at what I have written and understand what I did. Protecting attributes is part of #1, in that it limits unexpected outcomes of your program.The links here offers some other ways around Get/Set.  If you are working on your own project, use what you like and be consistent.  If you are on a group project follow the group guidelines (assuming they have them).   ;Quote:Original post by Atrix256Getters and setters aren't bad, they are good.The (main) reason getter/setter combos are generally discouraged has already been mentioned in this thread, and has probably been mentioned in just about every previous thread on this topic as well (a forum archive search for 'getter setter' should turn up some of these threads).If you're going to be changing some property of an object directly, then sure, having an opportunity to perform data validation or set a breakpoint could be useful. The (potential) problem with getter/setter combos though is simply the fact that it makes the properties of an object part of the public interface, thereby decreasing encapsulation.It can also be argued that in good object-oriented design, objects should 'do stuff' rather than 'have stuff done to them'. For example, rather than GetPos() and SetPos() for a game entity, you might have MoveRelative(), MoveTo(), and so on.There are no absolutes of course, and sometimes a getter/setter combo might be appropriate. But to say generally that 'getters and setters aren't bad, they are good', I think, pretty much goes against the conventional wisdom, at least as far as C++ is concerned.   