Search Results

Search found 432 results on 18 pages for 'setters'.

Page 1/18 | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • When are Getters and Setters Justified

    - by Winston Ewert
    Getters and setters are often criticized as being not proper OO. On the other hand most OO code I've seen has extensive getters and setters. When are getters and setters justified? Do you try to avoid using them? Are they overused in general? If your favorite language has properties (mine does) then such things are also considered getters and setters for this question. They are same thing from an OO methodology perspective. They just have nicer syntax. Sources for Getter/Setter Criticism (some taken from comments to give them better visibility): http://www.javaworld.com/javaworld/jw-09-2003/jw-0905-toolbox.html http://typicalprogrammer.com/?p=23 http://c2.com/cgi/wiki?AccessorsAreEvil http://www.darronschall.com/weblog/2005/03/no-brain-getter-and-setters.cfm http://www.adam-bien.com/roller/abien/entry/encapsulation_violation_with_getters_and To state the criticism simply: Getters and Setters allow you to manipulate the internal state of objects from outside of the object. This violates encapsulation. Only the object itself should care about its internal state. And an example Procedural version of code. struct Fridge { int cheese; } void go_shopping(Fridge fridge) { fridge.cheese += 5; } Mutator version of code: class Fridge { int cheese; void set_cheese(int _cheese) { cheese = _cheese; } int get_cheese() { return cheese; } } void go_shopping(Fridge fridge) { fridge.set_cheese(fridge.get_cheese() + 5); } The getters and setters made the code much more complicated without affording proper encapsulation. Because the internal state is accessible to other objects we don't gain a whole lot by adding these getters and setters. The question has been previously discussed on Stack Overflow: http://stackoverflow.com/questions/565095/java-are-getters-and-setters-evil http://stackoverflow.com/questions/996179

    Read the article

  • What Getters and Setters should and shouldn't do.

    - by cyclotis04
    I've run into a lot of differing opinions on Getters and Setters lately, so I figured I should make it into it's own question. A previous question of mine received an immediate comment (later deleted) that stated setters shouldn't have any side effects, and a SetProperty method would be a better choice. Indeed, this seems to be Microsoft's opinion as well. However, their properties often raise events, such as Resized when a form's Width or Height property is set. OwenP also states "you shouldn't let a property throw exceptions, properties shouldn't have side effects, order shouldn't matter, and properties should return relatively quickly." Yet Michael Stum states that exceptions should be thrown while validating data within a setter. If your setter doesn't throw an exception, how could you effectively validate data, as so many of the answers to this question suggest? What about when you need to raise an event, like nearly all of Microsoft's Control's do? Aren't you then at the mercy of whomever subscribed to your event? If their handler performs a massive amount of information, or throws an error itself, what happens to your setter? Finally, what about lazy loading within the getter? This too could violate the previous guidelines. What is acceptable to place in a getter or setter, and what should be kept in only accessor methods?

    Read the article

  • Java - Should private instance variables be accessed in constructors through getters and setters met

    - by Yatendra Goel
    I know that private instance variables are accessed through their public getters and setters method. But when I generate constructors with the help of IDE, it initializes instance variables directly instead of initializing them through their setter methods. Q1. So should I change the IDE generated code for constructors to initialize those instance variables through their setter methods. Q2. If yes, then why IDE don't generate constructors code in that way?

    Read the article

  • Data classes: getters and setters or different method design

    - by Frog
    I've been trying to design an interface for a data class I'm writing. This class stores styles for characters, for example whether the character is bold, italic or underlined. But also the font-size and the font-family. So it has different types of member variables. The easiest way to implement this would be to add getters and setters for every member variable, but this just feels wrong to me. It feels way more logical (and more OOP) to call style.format(BOLD, true) instead of style.setBold(true). So to use logical methods insteads of getters/setters. But I am facing two problems while implementing these methods: I would need a big switch statement with all member variables, since you can't access a variable by the contents of a string in C++. Moreover, you can't overload by return type, which means you can't write one getter like style.getFormatting(BOLD) (I know there are some tricks to do this, but these don't allow for parameters, which I would obviously need). However, if I would implement getters and setters, there are also issues. I would have to duplicate quite some code because styles can also have a parent styles, which means the getters have to look not only at the member variables of this style, but also at the variables of the parent styles. Because I wasn't able to figure out how to do this, I decided to ask a question a couple of weeks ago. See Object Oriented Programming: getters/setters or logical names. But in that question I didn't stress it would be just a data object and that I'm not making a text rendering engine, which was the reason one of the people that answered suggested I ask another question while making that clear (because his solution, the decorator pattern, isn't suitable for my problem). So please note that I'm not creating my own text rendering engine, I just use these classes to store data. Because I still haven't been able to find a solution to this problem I'd like to ask this question again: how would you design a styles class like this? And why would you do that? Thanks on forehand!

    Read the article

  • Javascript setters/getters

    - by Martin Hansen
    var author = { firstname: 'Martin', lastname: 'Hansen' } function settersGetters(propStr) { for (var i = 0; i < propStr.length; i++) { author['_'+ propStr[i]] = null; author.__defineGetter__(propStr[i], function() { return author['_'+ propStr[i]]; }); author.__defineSetter__(propStr[i], function(val) { author['_'+ propStr[i]] = val; }); }; } The above code would hopefully generate setters/getters for any supplied properties (in an array) for the object author. But when I call the below code Both firstname and lastname is olsen.. What am I doing wrong? settersGetters(['firstname', 'lastname']); author.firstname = 'per'; author.lastname = 'olsen'; console.log(author.firstname); console.log(author.lastname);

    Read the article

  • [PHP] Difference between normal and magic setters and getters

    - by Saif Bechan
    I am using a magic getter/setter class for my session variables, but I don't see any difference between normal setters and getters. The code: class session { public function __set($name, $value) { $_SESSION[$name] = $value; } public function __unset($name) { unset($_SESSION[$name]); } public function __get($name) { if(isset($_SESSION[$name])) { return $_SESSION[$name]; } } } Now the first thing I noticed is that I have to call $session->_unset('var_name') to remove the variable, nothing 'magical' about that. Secondly when I try to use $session->some_var this does not work. I can only get the session variable using $_SESSION['some_var']. I have looked at the PHP manual but the functions look the same as mine. Am I doing something wrong, or is there not really anything magic about these functions.

    Read the article

  • Difference between normal and magic setters and getters

    - by Saif Bechan
    I am using a magic getter/setter class for my session variables, but I don't see any difference between normal setters and getters. The code: class session { public function __set($name, $value) { $_SESSION[$name] = $value; } public function __unset($name) { unset($_SESSION[$name]); } public function __get($name) { if(isset($_SESSION[$name])) { return $_SESSION[$name]; } } } Now the first thing I noticed is that I have to call $session->_unset('var_name') to remove the variable, nothing 'magical' about that. Secondly when I try to use $session->some_var this does not work. I can only get the session variable using $_SESSION['some_var']. I have looked at the PHP manual but the functions look the same as mine. Am I doing something wrong, or is there not really anything magic about these functions.

    Read the article

  • What should be allowed inside getters and setters?

    - by Botond Balázs
    I got into an interesting internet argument about getter and setter methods and encapsulation. Someone said that all they should do is an assignment (setters) or a variable access (getters) to keep them "pure" and ensure encapsulation. Am I right that this would completely defeat the purpose of having getters and setters in the first place and validation and other logic (without strange side-effects of course) should be allowed? When should validation happen? When setting the value, inside the setter (to protect the object from ever entering an invalid state - my opinion) Before setting the value, outside the setter Inside the object, before each time the value is used Is a setter allowed to change the value (maybe convert a valid value to some canonical internal representation)?

    Read the article

  • DI and hypothetical readonly setters in C#

    - by Luis Ferrao
    Sometimes I would like to declare a property like this: public string Name { get; readonly set; } I am wondering if anyone sees a reason why such a syntax shouldn't exist. I believe that because it is a subset of "get; private set;", it could only make code more robust. My feeling is that such setters would be extremely DI friendly, but of course I'm more interested in hearing your opinions than my own, so what do you think? I am aware of 'public readonly' fields, but those are not interface friendly so I don't even consider them. That said, I don't mind if you bring them up into the discussion Edit I realize reading the comments that perhaps my idea is a little confusing. The ultimate purpose of this new syntax would be to have an automatic property syntax that specifies that the backing private field should be readonly. Basically declaring a property using my hypothetical syntax public string Name { get; readonly set; } would be interpreted by C# as: private readonly string name; public string Name { get { return this.name; } } And the reason I say this would be DI friendly is because when we rely heavily on constructor injection, I believe it is good practice to declare our constructor injected fields as readonly.

    Read the article

  • The use of getters and setters for different programming languages [closed]

    - by leonhart88
    So I know there are a lot of questions on getters and setters in general, but I couldn't find something exactly like my question. I was wondering if people change the use of get/set depending on different languages. I started learning with C++ and was taught to use getters and setters. This is what I understand: In C++ (and Java?), a variable can either be public or private, but we cannot have a mix. For example, I can't have a read-only variable that can still be changed inside the class. It's either all public (can read and change it), or all private (can't read and can only change inside the class). Because of this (and possibly other reasons), we use getters and setters. In MATLAB, I can control the "setaccess" and "getaccess" properties of variables, so that I can make things read-only (can directly access the property, but can't overwrite it). In this case, I don't feel like I need a getter because I can just do class.property. Also, in Python it is considered "Pythonic" to not use getters/setters and to only put things into properties if needed. I don't really understand why its OK to have all public variables in Python, because that's opposite of what I learned when I started with C++. I'm just curious what other people's thoughts are on this. Would you use getters and setters for all languages? Would you only use it for C++/Java and do direct access in MATLAB and Python (which is what I am currently doing)? Is the second option considered bad? For my purposes, I am only referring to simple getters and setters (just return/set the value and do not do anything else). Thanks!

    Read the article

  • Java Interface Usage Guidelines -- Are getters and setters in an interface bad?

    - by user68759
    What do people think of the best guidelines to use in an interface? What should and shouldn't go into an interface? I've heard people say that, as a general rule, an interface must only define behavior and not state. Does this mean that an interface shouldn't contain getters and setters? My opinion: Maybe not so for setters, but sometimes I think that getters are valid to be placed in an interface. This is merely to enforce the implementation classes to implement those getters and so to indicate that the clients are able to call those getters to check on something, for example.

    Read the article

  • Implicit vs explicit getters/setters in AS3, which to use and why?

    - by James
    Since the advent of AS3 I have been working like this: private var loggy:String; public function getLoggy ():String { return loggy; } public function setLoggy ( loggy:String ):void { // checking to make sure loggy's new value is kosher etc... this.loggy = loggy; } and have avoided working like this: private var _loggy:String; public function get loggy ():String { return loggy; } public function set loggy ( loggy:String ):void { // checking to make sure loggy's new value is kosher etc... this.loggy = loggy; } I have avoided using AS3's implicit getters/setters partly so that I can just start typing "get.." and content assist will give me a list of all my getters, and likewise for my setters. I also dislike underscores in my code which turned me off the implicit route. Another reason is that I prefer the feel of this: whateverObject.setLoggy( "loggy's awesome new value!" ); to this: whateverObject.loggy = "loggy's awesome new value!"; I feel that the former better reflects what is actually happening in the code. I am calling functions, not setting values directly. After installing Flash Builder and the great new plugin SourceMate ( which helps to get some of the useful features that FDT is famous into FB ) I realized that when I use SourceMate's "generate getters and setters" feature it automatically sets my code up using the implicit route: private var _loggy:String; public function get loggy ():String { return loggy; } public function set loggy ( loggy:String ):void { // do whatever is needed to check to make sure loggy is an acceptable value this.loggy = loggy; } I figure that these SourceMate people must know what they are doing or they wouldn't be writing workflow enhancement plugins for coding in AS3, so now I am questioning my ways. So my question to you is: Can anyone give me a good reason why I should give up my explicit g/s ways, start using the implicit technique, and embrace those stinky little _underscores for my private vars? Or back me up in my reasons for doing things the way that I do?

    Read the article

  • Problem with DataTrigger binding - setters are not being called

    - by aoven
    I have a Command bound to a Button in XAML. When executed, the command changes a property value on the underlying DataContext. I would like the button's Content to reflect the new value of the property. This works*: <Button Command="{x:Static Member=local:MyCommands.TestCommand}" Content="{Binding Path=TestProperty, Mode=OneWay}" /> But this doesn't: <Button Command="{x:Static Member=local:MyCommands.TestCommand}"> <Button.Style> <Style TargetType="{x:Type Button}"> <Style.Triggers> <DataTrigger Binding="{Binding Path=TestProperty, Mode=OneWay}" Value="True"> <DataTrigger.Setters> <Setter Property="Content" Value="Yes"/> </DataTrigger.Setters> </DataTrigger> <DataTrigger Binding="{Binding Path=TestProperty, Mode=OneWay}" Value="False"> <DataTrigger.Setters> <Setter Property="Content" Value="No"/> </DataTrigger.Setters> </DataTrigger> </Style.Triggers> </Style> </Button.Style> </Button> Why is that? * By "works" I mean the Content gets updated whenever I click the button. TIA

    Read the article

  • Can Eclipse generate method-chaining setters

    - by Chris R
    I'd like to generate method-chaining setters (setters that return the object being set), like so: public MyObject setField (Object value) { this.field = value; return this; } This makes it easier to do one-liner instantiations, which I find easier to read: myMethod (new MyObject ().setField (someValue).setOtherField (someOtherValue)); Can Eclipse's templates be modified to do this? I've changed the content to include return this; but the signature is not changed.

    Read the article

  • Getters and Setters are bad OO design?

    - by Dan
    Getters and Setters are bad Briefly reading over the above article I find that getters and setters are bad OO design and should be avoided as they go against Encapsulation and Data Hiding. As this is the case how can it be avoided when creating objects and how can one model objects to take this into account. In cases where a getter or setter is required what other alternatives can be used? Thanks.

    Read the article

  • How to make Spring accept non-void setters?

    - by Chris
    Hi, I have an API which I am turning into an internal DSL. As such, most methods in my PoJos return a reference to this so that I can chain methods together declaratively as such (syntactic sugar). myComponent .setID("MyId") .setProperty("One","1") .setProperty("Two","2") .setAssociation(anotherComponent) .execute(); My API does not depend on Spring but I wish to make it 'Spring-Friendly' by being PoJo friendly with zero argument constructors, getters and setters. The problem is that Spring seems to not detect my setter methods when I have a non-void return type. The return type of this is very convenient when chaining together my commands so I don't want to destroy my programmatic API just be to compatible with Spring injection. Is there a setting in Spring to allow me to use non-void setters? Chris

    Read the article

  • Getters and Setters: Code smell, Necessary Evil, or Can't Live Without Them [closed]

    - by Avery Payne
    Possible Duplicate: Allen Holub wrote “You should never use get/set functions”, is he correct? Is there a good, no, a very good reason, to go through all the trouble of using getters and setters for object-oriented languages? What's wrong with just using a direct reference to a property or method? Is there some kind of "semantical coverup" that people don't want to talk about in polite company? Was I just too tired and fell asleep when someone walked out and said "Thou Shalt Write Copious Amounts of Code to Obtain Getters and Setters"? Follow-up after a year: It seems to be a common occurrence with Java, less so with Python. I'm beginning to wonder if this is more of a cultural phenomena (related to the limitations of the language) rather than "sage advice". The -1 question score is complete for-the-lulz as far as I am concerned. It's interesting that there are specific questions that are downvoted, not because they are "bad questions", but rather, because they hit someone's raw nerve.

    Read the article

  • Responding to setters

    - by Simon Cave
    What is the best way to respond to data changes when property setters are called. For example, if I have a property called data, how can I react when [object setData:newData] is called and still use the synthesised setter. Instinctively, I would override the synthesised setter like so: - (void)setData:(DataObject *)newData { // defer to synthesised setter [super setData:newData]; // react to new data ... } ...but of course this doesn't make sense - I can't use super like this. So what is the best way to handle this situation? Should I be using KVO? Or something else?

    Read the article

  • Auto-implemented getters and setters vs. public fields

    - by tclem
    I see a lot of example code for C# classes that does this: public class Point { public int x { get; set; } public int y { get; set; } } Or, in older code, the same with an explicit private backing value and without the new auto-implemented properties: public class Point { private int _x; private int _y; public int x { get { return _x; } set { _x = value; } } public int y { get { return _y; } set { _y = value; } } } My question is why. Is there any functional difference between doing the above and just making these members public fields, like below? public class Point { public int x; public int y; } To be clear, I understand the value of getters and setters when you need to do some translation of the underlying data. But in cases where you're just passing the values through, it seems needlessly verbose.

    Read the article

  • Which order to define getters and setters in? [closed]

    - by N.N.
    Is there a best practice for the order to define getters and setters in? There seems to be two practices: getter/setter pairs first getters, then setters (or the other way around) To illuminate the difference here is a Java example of getter/setter pairs: public class Foo { private int var1, var2, var3; public int getVar1() { return var1; } public void setVar1(int var1) { this.var1 = var1; } public int getVar2() { return var2; } public void setVar2(int var2) { this.var2 = var2; } public int getVar3() { return var3; } public void setVar3(int var3) { this.var3 = var3; } } And here is a Java example of first getters, then setters: public class Foo { private int var1, var2, var3; public int getVar1() { return var1; } public int getVar2() { return var2; } public int getVar3() { return var3; } public void setVar1(int var1) { this.var1 = var1; } public void setVar2(int var2) { this.var2 = var2; } public void setVar3(int var3) { this.var3 = var3; } } I think the latter type of ordering is clearer both in code and in class diagrams but I do not know if that is enough to rule out the other type of ordering.

    Read the article

1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >