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  • Using static methods in objects PHP - is it advantage?

    - by RePRO
    I was reading some articles and discussions on the use of static methods on objects and it struck me how much the views differ. Someone say that using static methods is an advantage. Someone says that use is a big mistake. I wonder how is it? My question is when to use static methods and when not? I would like to hear answers from experts in this field (PHP OOP). This is because I know how it really is. The following code should be analogous. Just call the static method is simpler (my opinion): <?php class A { public function write($a) { echo $a; } } class B { public static function write($a) { echo $a; } } $a = new A; $a->write(5); // 5 B::write(5); // 5 ?> Thank you.

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  • The sign of a true manager is delegation (C# style)

    - by MarkPearl
    Today I thought I would write a bit about delegates in C#. Up till recently I have managed to side step any real understanding of what delegates do and why they are useful – I mean, I know roughly what they do and have used them a lot, but I have never really got down dirty with them and mucked about. Recently however with my renewed interest in Silverlight delegates came up again as a possible solution to a particular problem, and suddenly I found myself opening a bland little console application to just see exactly how far I could take delegates with my limited knowledge. So, let’s first look at the MSDN definition of delegates… A delegate declaration defines a reference type that can be used to encapsulate a method with a specific signature. A delegate instance encapsulates a static or an instance method. Delegates are roughly similar to function pointers in C++; however, delegates are type-safe and secure. Well, don’t you love MSDN for such a useful definition. I must give it credit though… later on it really explains it a bit better by saying “A delegate lets you pass a function as a parameter. The type safety of delegates requires the function you pass as a delegate to have the same signature as the delegate declaration.” A little more reading up on delegates mentions that delegates are similar to interfaces in that they enable the separation of specification and implementation. A delegate declares a single method, while an interface declares a group of methods. So enough reading - lets look at some code and see a basic example of a delegate… Let’s assume we have a console application with a simple delegate declared called AdjustValue like below… class Program { private delegate int AdjustValue(int val); static void Main(string[] args) { } } In a sense, all we have said is that we will be creating one or more methods that follow the same pattern as AdjustValue – i.e. they will take one input value of type int and return an integer. We could then expand our code to have various methods that match the structure of our delegate AdjustValue (remember the structure is int xxx (int xxx)) class Program { private delegate int AdjustValue(int val); private static int Dbl(int val) { return val * 2; } private static int AlwaysOne(int val) { return 1; } static void Main(string[] args) { } }  Above I have expanded my project to have two methods, one called Dbl and the other AlwaysOne. Dbl always returns double the input val and AlwaysOne always returns 1. I could now declare a variable and assign it to be one of those functions, like the following… class Program { private delegate int AdjustValue(int val); private static int Dbl(int val) { return val * 2; } private static int AlwaysOne(int val) { return 1; } static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; Console.WriteLine(myDelegate(1).ToString()); Console.ReadLine(); } } In this instance I have declared an instance of the AdjustValue delegate called myDelegate; I have then told myDelegate to point to the method Dbl, and then called myDelegate(1). What would the result be? Yes, in this instance it would be exactly the same as me calling the following code… static void Main(string[] args) { Console.WriteLine(Dbl(1).ToString()); Console.ReadLine(); }   So why all the extra work for delegates when we could just do what we did above and call the method directly? Well… that separation of specification to implementation comes to mind. So, this all seems pretty simple. Let’s take a slightly more complicated variation to the console application. Assume that my project is the same as the one previously except that my main method is adjusted as follows… static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; myDelegate = AlwaysOne; Console.WriteLine(myDelegate(1).ToString()); Console.ReadLine(); } What would happen in this scenario? Quite simply “1” would be written to the console, the reason being that myDelegate was last pointing to the AlwaysOne method before it was called. Make sense? In a way, the myDelegate is a variable method that can be swapped and changed when needed. Let’s make the code a little more confusing by using a delegate in the declaration of another delegate as shown below… class Program { private delegate int AdjustValue(InputValue val); private delegate int InputValue(); private static int Dbl(InputValue val) { return val()*2; } private static int GetInputVal() { Console.WriteLine("Enter a whole number : "); return Convert.ToInt32(Console.ReadLine()); } static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; Console.WriteLine(myDelegate(GetInputVal).ToString()); Console.ReadLine(); } }   Now it gets really interesting because it looks like we have passed a method into a function in the main method by declaring… Console.WriteLine(myDelegate(GetInputVal).ToString()); So, what it the output? Well, try take a guess on what will happen – then copy the code and see if you got it right. Well that brings me to the end of this short explanation of Delegates. Hopefully it made sense!

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  • &ldquo;Fixing&rdquo; T-SQL

    In a comment to my previous post, Rich asked Does this mean you're the person to fix T-SQL programmability? I honestly dont know the answer to that question because, coming from the outside, Im not sure about everything thats wrong with T-SQL. Id love to hear more from anyone whos got an opinion (and any pointers to complaints around the web would be welcome as well). You can also feel free to use my contact form to talk to me directly. I cant promise I can do anything at this point, but Im...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • If you should only have one assertion per test; how to test multiple inputs?

    - by speg
    I'm trying to build up some test cases, and have read that you should try and limit the number of assertions per test case. So my question is, what is the best way to go about testing a function w/ multiple inputs. For example, I have a function that parses a string from the user and returns the number of minutes. The string can be in the form "5w6h2d1m", where w, h, d, m correspond to the number of weeks, hours, days, and minutes. If I wanted to follow the '1 assertion per test rule' I'd have to make multiple tests for each variation of input? That seems silly so instead I just have something like: self.assertEqual(parse_date('5m'), 5) self.assertEqual(parse_date('5h'), 300) self.assertEqual(parse_date('5d') ,7200) self.assertEqual(parse_date('1d4h20m'), 1700) In the one test case. Is there a better way?

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  • Android Loading Screen: How do I go about using a stack to load elements, and the option of incrementing the size counter?

    - by tom_mai78101
    I have some problems with figuring out what value I should put in the function: int value_needed_to_figure_out = X; ProgressBar.incrementProgressBy(value_needed_to_figure_out); I've been researching about loading screens and how to use them. Some examples I've seen have implemented Thread.sleep() in a Handler.post(new Runnable()) function. To me, I got most of that concept of using the Handler to update the ProgressBar, while pretending to do some heavy crunching work. So, I kept looking. I have read this thread here: How do I load chunks of data from an assest manager during a loading screen? It said that I can try using a stack it needs to load, and adding a size counter as I add elements to the stack. What does it mean? This is the part where I'm totally stumped. If anyone would provide some hints, I'll gladly appreciate it. Thanks in advance.

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  • Shared Object Not saving the level Progress

    - by user3536228
    I am making a flash game in which i have a variable levelState that describes the current level in which user has entered I am using SharedObject to save the progress but it does not do so first i declred a clas level variable private var levelState:Number = 1; private var mySaveData:SharedObject = SharedObject.getLocal("levelSave"); in the Main function i am checking if it is a first run of the game like below if (mySaveData.data.levelsComplete == null) { mySaveData.data.levelsComplete = 1; } and in a function where the winning condition is checked so that levelState could be increased i am usin this sharedobject to hold the value of levelState if (/*winniing condition*/) levelState++; mySaveData.data.levelsComplete = levelState; mySaveData.flush(); setNewLevel(levelState); } but when i play the game clear a level and again run the game it does not start from that level it starts from beginning.

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  • Tension between the dependency inversion principle and avoiding "new" in C++?

    - by Kazark
    I have seen a lot of advice that it is better to do Type object; than Type* object = new Type(); in C++ whenever possible. I understand the rational behind this and appreciate it. But according to my understanding, to practice dependency inversion requires pointers, e.g.: Type* object = new Implementation();. (Or am I wrong about that?) Is there an inherent tension between the DIP and avoiding new when using C++? If so, what patterns/principles/practices can be used to mitigate this tension?

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  • where does the discrepancy between \# in PS1 and n in !n come from?

    - by Cbhihe
    Something has been gnawing at me for a while now and I can't seem to find a relevant answer either in man pages or using your 'Don't be evil' search engine. My .bashrc has the following: shopt -s histappend HISTSIZE=100 HISTFILESIZE=0 # 200 previous value Putting HISTFILESIZE to 0 allows me to start with a clean history slate with each new term window. I find it practical in conjunction with using a prompt that contains \#, because when visualizing a previous command before recalling it with !n or !-p, one can just do: $ history | more to see its relevant "n" value In my case, usually the result of: $ \history | tail -1 | awk '{print $1}' # (I know this is an overkill, don't flame me) equals the expanded value of # in PS1 minus 1, which is how I like it to be at all times. But then, sometimes not. At times the expanded value of # sort of "runs away". It's incremented in such a a manner that it becomes than $(( $(\history | tail -1 | awk '{print $1}')+1 )) Any pointers, anyone?

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  • Keep coding the wrong way to remain consistent? [closed]

    - by bwalk2895
    Possible Duplicate: Code maintenance: keeping a bad pattern when extending new code for being consistent, or not? To keep things simple let's say I am responsible for maintaining two applications, AwesomeApp and BadApp (I am responsible for more and no that is not their actual names). AwesomeApp is a greenfield project I have been working on with other members on my team. It was coded using all the fancy buzzwords, Multilayer, SOA, SOLID, TDD, and so on. It represents the direction we want to go as a team. BadApp is a application that has been around for a long time. The architecture suffers from many sins, namely everything is tightly coupled together and it is not uncommon to get a circular dependency error from the compiler, it is almost impossible to unit test, large classes, duplicate code, and so on. We have a plan to rewrite the application following the standards established by AwesomeApp, but that won't happen for a while. I have to go into BadApp and fix a bug, but after spending months coding what I consider correctly, I really don't want do continue perpetuate bad coding practices. However, the way AwesomeApp is coded is vastly different from the way BadApp is coded. I fear implementing the "correct" way would cause confusion for other developers who have to maintain the application. Question: Is it better to keep coding the wrong way to remain consistent with the rest of the code in the application (knowing it will be replaced) or is it better to code the right way with an understanding it could cause confusion because it is so much different? To give you an example. There is a large class (1000+ lines) with several functions. One of the functions is to calculate a date based on an enumerated value. Currently the function handles all the various calculations. The function relies on no other functionality within the class. It is self contained. I want to break the function into smaller functions (at the very least) and put them into their own classes and hide those classes behind an interface (at the most) and use the factory pattern to instantiate the date classes. If I just broke it out into smaller functions within the class it would follow the existing coding standard. The extra steps are to start following some of the SOLID principles.

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  • vlc 1.1.9 not working properly

    - by jaggib
    I have installed vlc 1.1.9 on wubi installed Ubuntu 11.04 using Ubuntu Software Center. Now when i tried playing videos in vlc (any format) full screen mode doesnt show controls and usually doesnt gets me out to window mode. it sometimes crashes to login screen. I tried the video output to 'X11 output mode' and 'XVideo output (XCB)' but the above problem persists and also bring another problem. full screen mode doesnt responds always when it does, it shows the video over the desktop instead of inside the player. the only way to get ubuntu to function normally is to restart the system. I tried with not using the 'Embed video in interface' but still the same problem. vlc runs perfectly well in windows. How can i make vlc function properly on my system or i need to install another player? My system config is: Graphics: VIA/S3G UniChrome Pro IGP Processor: AMD Sempron(tm) Processor 2800+ RAM: 1.5GB Motherboard Name: MS-7181 (MSI)

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  • Separating portion of website to its own server

    - by Brett
    So my job is to take the homepage (or maybe I should say "homesite" because it encompasses a few interrelated pages) and drag this onto its own Apache server. The problem I'm having right now is being able to weed out jumbled/bundled files (such as folders of js, css, and other files that i cant even identify) and knowing what is necessary to keep the homesite running. I'm new to this stuff (I'm an intern) so feel free to ask questions if I'm leaving vital information out. What I'm asking of you guys here is basically any pointers or tips you may be able to give me in order to get the job done. I could use some advice from people with a little more experience in web development. btw: This question may appear as though I have not completed any prior research and that is, for the most part, true. But the problem is I really am not sure how to research this. If you guys could throw me some keywords to play with that would really be helpful. Thanks!

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  • Point me to info about constructing filters (of lists)

    - by jah
    I would like some pointers to information which would help me understand how to go about providing the ability to filter a list of entities by their attributes as well as by attributes of related entities. As an example, imagine a web app which provides order management of some kind. Orders and related entities are stored in a relational database. And imagine that the app has an interface which lists the orders. The problem is: how does one allow the list to be filtered by, for example:- order number (an attribute) line item name (an attribute of a n-n related entity) some text in an administrative note related to the order (text found in an attribute of a 1-1 related entity) I'm trying to discover whether there is something like a standard, efficient way to construct the queries and the filtering form; or some possible strategies; or any theory on the topic; or some example code. My google foo fails me.

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  • T-SQL Tuesday: What kind of Bookmark are you using?

    - by Kalen Delaney
    I’m glad there is no minimum length requirement for T-SQL Tuesday blog posts , because this one will be short. I was in the classroom for almost 11 hours today, and I need to be back tomorrow morning at 7:30. Way long ago, back in SQL 2000 (or was it earlier?) when a query indicated that SQL Server was going to use a nonclustered index to get row pointers, and then look up those rows in the underlying table, the plan just had a very linear look to it. The operator that indicated going from the nonclustered...(read more)

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  • Take Camera Phone Macro Photos with a Cheap Laser Pointer Lens

    - by Jason Fitzpatrick
    Inside those cheap laser pointers you see in the grocery store checkout line there’s a handy little plastic lens that, when slapped on your phone’s camera, makes it easy to take macro photographs. In this tutorial, they take the lens from a laser point and secure it using tape and a bobby pin. An alternative method to achieve the same end (and with a higher quality lens) is to dismantle a CD/DVD drive to source the lens and use painter’s tape to hold the lens in place–this is the technique I used several years ago, check out the tutorial video here. Laser Pointer Macro Lens [via Apartment Therapy] How to Get Pro Features in Windows Home Versions with Third Party Tools HTG Explains: Is ReadyBoost Worth Using? HTG Explains: What The Windows Event Viewer Is and How You Can Use It

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  • Where to start for writing a simple java IDE?

    - by AedonEtLIRA
    I would like to start working on my own custom IDE. The biggest reason I want to work on the IDE is to help me gain an even greater, more intimate understanding of java (and other languages I add into it.) I don't want to do anything super fancy or revolutionary, I'd be happy if I could create something as compact as the BlueJ IDE I used in high school and be content. I have a few question on the specifics of the task that I hope I can get cleared up before I start investing time in this: Is there anything I should be aware of when writing the parser? Does anyone have any pointers that I should be aware of; pitfalls, brick walls or other constraints?

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  • How to write this kind of java source in clojure. [closed]

    - by tikky
    I want to know how to write a clojure code by looking at a java code like this. import xxxxxx import com.vaadin.terminal.gwt.server.AbstractApplicationServlet; public class Clojure4Vaadin extends AbstractApplicationServlet { @Override protected Class <? extends Application > getApplicationClass() throws ClassNotFoundException { return Application.class; } @Override protected Application getNewApplication(HttpServletRequest request) throws ServletException { try { RT.load(getServletConfig().getInitParameter("script-name"), true); //run Lisp function return (Application)RT.var(getServletConfig().getInitParameter("package-name"),getServletConfig().getInitParameter("function-name")).invoke(new String[0]); } catch (Exception e) { throw new ServletException(e); } } } I need to write a code clojure code which can do the sane thing that this java code can do.

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  • Practices for domain models in Javascript (with frameworks)

    - by AndyBursh
    This is a question I've to-and-fro'd with for a while, and searched for and found nothing on: what're the accepted practices surrounding duplicating domain models in Javascript for a web application, when using a framework like Backbone or Knockout? Given a web application of a non-trivial size with a set of domain models on the server side, should we duplicate these models in the web application (see the example at the bottom)? Or should we use the dynamic nature to load these models from the server? To my mind, the arguments for duplicating the models are in easing validation of fields, ensuring that fields that expected to be present are in fact present etc. My approach is to treat the client-side code like an almost separate application, doing trivial things itself and only relying on the server for data and complex operations (which require data the client-side doesn't have). I think treating the client-side code like this is akin to separation between entities from an ORM and the models used with the view in the UI layer: they may have the same fields and relate to the same domain concept, but they're distinct things. On the other hand, it seems to me that duplicating these models on the server side is a clear violation of DRY and likely to lead to differing results on the client- and server-side (where one piece gets updated but the other doesn't). To avoid this violation of DRY we can simply use Javascripts dynamism to get the field names and data from the server as and when they're neeed. So: are there any accepted guidelines around when (and when not) to repeat yourself in these situations? Or this a purely subjective thing, based on the project and developer(s)? Example Server-side model class M { int A DateTime B int C int D = (A*C) double SomeComplexCalculation = ServiceLayer.Call(); } Client-side model function M(){ this.A = ko.observable(); this.B = ko.observable(); this.C = ko.observable(); this.D = function() { return A() * C(); } this.SomeComplexCalculation = ko.observalbe(); return this; }l M.GetComplexValue = function(){ this.SomeComplexCalculation(Ajax.CallBackToServer()); }; I realise this question is quite similar to this one, but I think this is more about almost wholly untying the web application from the server, where that question is about doing this only in the case of complex calculation.

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  • How to avoid whitespace in PHP and ASP.NET? [closed]

    - by Goma
    You know that the PHP interpreter avoids whitespace and comments. However, I have heared that there is something you can do to make the interpreter does not see the whitespace at all and does not even think to avoid it, the same for the compiler in ASP.NET. What is that thing? Is it a function in PHP and a class in ASP.NET? or what exactly? Edit: For example the php_strip_whitespace function in PHP "Returns the PHP source code in filename with PHP comments and whitespace removed". Will this help in load time?

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  • Include in service layer all the application's functions or only the reusable ones?

    - by BornToCode
    Background: I need to build a main application with some operations (CRUD and more) (-in winforms), I need to make another application which will re-use some of the functions of the main application (-in webforms). I understood that using service layer is the best approach here. If I understood correctly the service should be calling the function on the BL layer (correct me if I'm wrong) The dilemma: In my main winform UI - should I call the functions from the BL, or from the service? (please explain why) Should I create a service for every single function on the BL even if I need some of the functions only in one UI? for example - should I create services for all the CRUD operations, even though I need to re-use only update operation in the webform? YOUR HELP IS MUCH APPRECIATED

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  • OpenGL VBOs are slower then glDrawArrays.

    - by Arelius
    So, this seems odd to me. I upload a large buffer of vertices, then every frame I call glBindbuffer and then the appropriate gl*Pointer functions with offsets into the buffer, then I use glDrawArrays to draw all of my triangles. I'm only drawing about 100K triangles, however I'm getting about 15FPS. This is where it gets weird, if I change it to not call glBindBuffer, then change the gl*Pointer calls to be actual pointers into the array I have in system memory, and then call glDrawArrays the same, my framerate jumps up to about 50FPS. Any idea what I weird thing I could be doing that would cause this? Did I maybe forget to call glEnable(GL_ALLOW_VBOS_TO_RUN_FAST) or something?

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  • "Whole-team" C++ features?

    - by Blaisorblade
    In C++, features like exceptions impact your whole program: you can either disable them in your whole program, or you need to deal with them throughout your code. As a famous article on C++ Report puts it: Counter-intuitively, the hard part of coding exceptions is not the explicit throws and catches. The really hard part of using exceptions is to write all the intervening code in such a way that an arbitrary exception can propagate from its throw site to its handler, arriving safely and without damaging other parts of the program along the way. Since even new throws exceptions, every function needs to provide basic exception safety — unless it only calls functions which guarantee throwing no exception — unless you disable exceptions altogether in your whole project. Hence, exceptions are a "whole-program" or "whole-team" feature, since they must be understood by everybody in a team using them. But not all C++ features are like that, as far as I know. A possible example is that if I don't get templates but I do not use them, I will still be able to write correct C++ — or will I not?. I can even call sort on an array of integers and enjoy its amazing speed advantage wrt. C's qsort (because no function pointer is called), without risking bugs — or not? It seems templates are not "whole-team". Are there other C++ features which impact code not directly using them, and are hence "whole-team"? I am especially interested in features not present in C. Update: I'm especially looking for features where there's no language-enforced sign you need to be aware of them. The first answer I got mentioned const-correctness, which is also whole-team, hence everybody needs to learn about it; however, AFAICS it will impact you only if you call a function which is marked const, and the compiler will prevent you from calling it on non-const objects, so you get something to google for. With exceptions, you don't even get that; moreover, they're always used as soon as you use new, hence exceptions are more "insidious". Since I can't phrase this as objectively, though, I will appreciate any whole-team feature. Appendix: Why this question is objective (if you wonder) C++ is a complex language, so many projects or coding guides try to select "simple" C++ features, and many people try to include or exclude some ones according to mostly subjective criteria. Questions about that get rightfully closed regularly here on SO. Above, instead, I defined (as precisely as possible) what a "whole-team" language feature is, provide an example (exceptions), together with extensive supporting evidence in the literature about C++, and ask for whole-team features in C++ beyond exceptions. Whether you should use "whole-team" features, or whether that's a relevant concept, might be subjective — but that only means the importance of this question is subjective, like always.

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  • MouseEvent.CLICK not working? (AS3)

    - by Jake
    ok so here's my code in AS3, I'd like to know why when i actually click on the picture, nothing happens. And if any of you have great tutorial of what to learn after classes/functions in AS3, let me know =D : package { import flash.display.Bitmap; import flash.display.Sprite; import flash.display.Shape; import flash.events.MouseEvent; public class Main extends Sprite { [Embed(source="../Pics/Picture.png")] private var HeroClass:Class; private var hero:Bitmap = new HeroClass(); public function Main():void { addChild(hero); hero.addEventListener(MouseEvent.CLICK, onClick); function onClick(e:MouseEvent):void { trace("hey"); hero.visible = false; } } } }

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  • Teaching java interfaces to absolute beginners: What is a good example? [closed]

    - by mrsteve
    Possible Duplicate: Explaining interfaces to beginning programmers? I searched on stackoverflow and here for a good example to teach java interfaces in a beginners class. I found the following post: http://stackoverflow.com/questions/416331/java-interfaces The Official Java-Tutorial and the references feature examples that are quite good but I would need a very simple example to start with for my class. I don't think the offical tutorial is the best resource for absolute beginners. The students are easily confused, and the most effective example would help. Any pointers or experience in teaching java interfaces?

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  • Where can I find good (well organized) examples of game code?

    - by smasher
    Where can I find good (well organized) examples of game code? I'm hoping that I can pick up some organizational tips. Most examples in books are too short and leave out lots of detail for the sake of brevity. I'm particularly interested on how to group your variables and methods so that another programmer would know where to look in the code. For example initializers at the top, then methods that take input, then methods that update views. I don't care about a particular language, as long as its OOP. I looked at the Quake 2 and 3 sources, but they're straight C and not much help for getting tips on organizing your objects. So, have you seen some good source? Any pointers to code that makes you say "wow, that's well organized" would be great.

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  • Script to calculate the Median value for SQL Server data

    The standard SQL language has a number of aggregate functions like: SUM, MIN, MAX, AVG, but a common statistics function that SQL Server does not have is a built-in aggregate function for median. The median is the value that falls in the middle of a sorted resultset with equal parts that are smaller and equal parts that are greater. Since there is no built-in implementation for the median, the following is a simple solution I put together to find the median. Get smart with SQL Backup ProPowerful centralised management, encryption and more.SQL Backup Pro was the smartest kid at school. Discover why.

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