Search Results

Search found 45849 results on 1834 pages for 'abstract class'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 36/1834 | < Previous Page | 32 33 34 35 36 37 38 39 40 41 42 43  | Next Page >

  • Perl OO frameworks and program design - Moose and Conway's inside-out objects (Class::Std)

    - by Emmel
    This is more of a use-case type of question... but also generic enough to be more broadly applicable: In short, I'm working on a module that's more or less a command-line wrapper; OO naturally. Without going into too many details (unless someone wants them), there isn't a crazy amount of complexity to the system, but it did feel natural to have three or four objects in this framework. Finally, it's an open source thing I'll put out there, rather than a module with a few developers in the same firm working on it. First I implemented the OO using Class::Std, because Perl Best Practices (Conway, 2005) made a good argument for why to use inside-out objects. Full control over what attributes get accessed and so on, proper encapsulation, etc. Also his design is surprisingly simple and clever. I liked it, but then noticed that no one really uses this; in fact it seems Conway himself doesn't really recommend this anymore? So I moved to everyone's favorite, Moose. It's easy to use, although way way overkill feature-wise for what I want to do. The big, major downside is: it's got a slew of module dependencies that force users of my module to download them all. A minor downside is it's got way more functionality than I really need. What are recommendations? Inconvenience fellow developers by forcing them to use a possibly-obsolete module, or force every user of the module to download Moose and all its dependencies? Is there a third option for a proper Perl OO framework that's popular but neither of these two?

    Read the article

  • javascript class calling XMLHttpRequest internally, then handling onreadystatechange

    - by Radu M
    this thing almost works: function myClass(url) { this.source = url; this.rq = null; this.someOtherProperty = "hello"; // open connection to the ajax server this.start = function() { if (window.XMLHttpRequest) { this.rq = new XMLHttpRequest(); if (this.rq.overrideMimeType) this.rq.overrideMimeType("text/xml"); } else this.rq = new ActiveXObject("Microsoft.XMLHTTP"); try { this.rq.onreadystatechange = connectionEvent; this.rq.open("GET", this.source, true); this.rq.send(null); this.state = 1; } catch (err) { // some error handler here } } function connectionEvent() { alert("i'm here"); alert("this doesnt work: " + this.someOtherProperty); } } // myClass so it's nothing more than having the XMLHttpRequest object as a member of my class, instead of globally defined, and invoking it in the traditional way. however, inside my connectionEvent callback function, the meaning of "this" is lost, even though the function itself is scoped inside myClass. i also made sure that the object that i instantiate from myClass is kept alive long enough (declared global in the script). in all the examples of using javascript classes that i saw, "this" was still available inside the inner functions. for me, it is not, even if i take my function outside and make it a myClass.prototype.connectionEvent. what am i doing wrong? thank you.

    Read the article

  • How to propagate .java file change to .class under eclipse, tomcat & stripes

    - by BigBourin
    Hi, i'm new to java and i got some problems. i'm developping a web application using the framework stripes on tomcat 6.0. I'm working with eclipse EE on windows. i successfully managed to get the stripes example application (called Bugzooky) up and running on my tomcat server. I imported the .war file and stripes libs in Eclipse. Here is the stripes archive containing the examples and libs But now i'm trying to change the example source files to learn how does it work. but whatever the modification made to the source files "WebContent/WEB-INF/src/*.java", nothing change! even after restarting the server. i noticed that the classes are compiled into .class files in the "ImportedClasses" folder, and tomcat always use these files, they are never updated, and if i removed one of them, the application just don't start. it look like my source files don't exists! I also tried to build my webapp from scratch, but when i tried to use the features used in the example files (like SecurityFilter.java): import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import ... It ends up with plenty of: the import javax.servlet.Filter cannot be resolved I checked the Librairies and it look like i'm using exactly the same as the example. It's probably something i didn't understood about java but i googled 100 times yesterday, and i can't find the solution (i probably didn't search the right place because i don't really understand my problem). I hope you'll be able to help me.

    Read the article

  • Dynamic Connection Strings for Strongly Typed DataSet in a Class Library using App.Config

    - by Luc
    This is my first question on StackOverflow.com and I'm not sure if this is the correct way to do this. I found a similar question titled: Modifying the Data Source for the Strongly Typed Dataset Connection String. However, the answer provided is not working for me. I'm not able to comment on it because I don't have enough "reputation points" (again, I just signed up), and I didn't want to provide an "answer", because I don't know the correct answer. My problem is that I need to be able to modify the connection string inside the generated myproject.dll.config file, but doing so has no effect for me at all. My library still uses the default connection string that was setup at design time. I've tried everything I know to try, but still no luck. I've tried working around the issue using multiple different approaches, but still the problem persists. I can't find any help on the internet with my specific problem either. It would be great if somebody could shed some light as to why my modified config file isn't being read. Useful information: I'm using a Strongly Typed DataSet I don't know the actual connection string at design time. The app.config doesn't allow me to specify a 'User' scoped connection string. I'm tied to a class library (no Windows Forms) Thank you for any help! Luc

    Read the article

  • C# class design - expose variables for reading but not setting

    - by James Brauman
    I have a a polygon class which stores a list of Microsoft.Xna.Framework.Vector2 as the vertices of the polygon. Once the polygon is created, I'd like other classes to be able to read the position of the vertices, but not change them. I am currently exposing the vertices through this field: /// <summary> /// Gets the vertices stored for this polygon. /// </summary> public List<Vector2> Vertices { get { return _vertices; } } List<Vector2> _vertices; However you can change any vertex using code like: Polygon1.Vertices[0] = new Vector2(0, 0); or Polygon1.Vertices[0].X = 0; How can I limit other classes to be able to only read the properties of these vertices, and not be able to set a new one to my List? The only thing I can think of is to pass a copy to classes that request it. Note that Vector2 is a struct that is part of the XNA framework and I cannot change it. Thanks.

    Read the article

  • targeting sprites from a method in the document class - null object reference

    - by Freddyk
    Hi I am trying to code a flash app entirely in the document class. I am using GestureWorks with a touch screen. When a user essentially presses a button it calls a method that should hide a specific graphic but not the graphic they touched. Essentially I need a way to refer to a graphic on the screen using a method besides 'e.target'. //This code works because it can access 'e.target'. private function photo1SpriteFlickHandler(e:GestureEvent):void { var openTween:Tween = new Tween(e.target, "x", Strong.easeOut, 232, 970, 5, true); } //this code gives me a null object reference because I am using 'photo1Sprite' rather than 'e.target' private function photo1SpriteFlickHandler(e:GestureEvent):void { var openTween:Tween = new Tween(photo1Sprite, "x", Strong.easeOut, 232, 970, 5, true); } //photo1Sprite has already been programatically added to the screen as so: var photo1Sprite = new TouchSprite(); var photo1Loader=new Loader(); photo1Loader.load(new URLRequest("media/photos1/photo1.jpg")); photo1Loader.contentLoaderInfo.addEventListener(Event.COMPLETE,loaderComplete); photo1Sprite.x = 232; photo1Sprite.y = 538; photo1Sprite.scaleX = .3; photo1Sprite.scaleY = .3; photo1Sprite.blobContainerEnabled = true; photo1Sprite.addEventListener(TouchEvent.TOUCH_DOWN, startDrag_Press); photo1Sprite.addEventListener(TouchEvent.TOUCH_UP, stopDrag_Release); photo1Sprite.addChild(photo1Loader); addChild(photo1Sprite); So I can make photo1Sprite react if my method is attached to it directly using 'e.target' but not if I am trying to call it from a method that was called from another element on the screen.

    Read the article

  • sorting a gridview in class

    - by user175084
    ok i have a project which has many gridview in its pages... now i am sorting the fridveiw using the sorting function like this: protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) { DataTable dt = Session["TaskTable2"] as DataTable; if (dt != null) { //Sort the data. dt.DefaultView.Sort = e.SortExpression + " " + GetSortDirection(e.SortExpression); GridView1.DataSource = Session["TaskTable2"]; GridView1.DataBind(); } } private string GetSortDirection(string column) { // By default, set the sort direction to ascending. string sortDirection2 = "ASC"; // Retrieve the last column that was sorted. string sortExpression2 = ViewState["SortExpression2"] as string; if (sortExpression2 != null) { // Check if the same column is being sorted. // Otherwise, the default value can be returned. if (sortExpression2 == column) { string lastDirection = ViewState["SortDirection2"] as string; if ((lastDirection != null) && (lastDirection == "ASC")) { sortDirection2 = "DESC"; } } } // Save new values in ViewState. ViewState["SortDirection2"] = sortDirection2; ViewState["SortExpression2"] = column; return sortDirection2; } but this code is being repeated in many pages so i tried to put this function in a C# class and try to call it but i get errors.... for starters i get the viewstate error saying :| "viewstate does not exist in the current context" so how do i go about doing this ....?? thanks

    Read the article

  • Issue with class design to model user preferences for different classes

    - by Mulone
    Hi all, I'm not sure how to design a couple of classes in my app. Basically that's a situation: each user can have many preferences each preference can be referred to an object of different classes (e.g. album, film, book etc) the preference is expressed as a set of values (e.g. score, etc). The problem is that many users can have preferences on the same objects, e.g.: John: score=5 for filmid=apocalypsenow Paul: score=3 for filmid=apocalypsenow And naturally I don't want to duplicate the object film in each user. So I could create a class called "preference" holding a score and then a target object, something like: User{ hasMany preferences } Preference{ belongsTo User double score Film target Album target //etc } and then define just one target. Then I would create an interface for the target Classes (album, film etc): Interface canBePreferred{ hasMany preferences } And implement all of those classes. This could work, but it looks pretty ugly and it would requires a lot of joins to work. Do you have some patterns I could use to model this nicely? Cheers, Mulone

    Read the article

  • I cant put a string in a switch nor an array in a class

    - by TimothyTech
    Okay, im making a pretty big file in my opinion, so i wanted to separate it into several files for cleaner code. so i have my main .cpp file and two header files holding my classes. well the header files dont hold strings, it aboslutely wont budge. i call the library in both my .cpp file and even tried it in my header file. another issue i ran into is using strings to make switches function, reason being if i use integers in a switch if the user inputs a alphabetical character the program goes into an endless loop. string choice; switch (choice) { case "1" : //... break; case "2" : //... break; } and my last issue is when i create an object in a case it gives an error. says cross initialization of object. string choice; switch (choice) { case "1" : Class object; break; case "2" : //... break; }

    Read the article

  • Defining a Class in Objective C, XCode

    - by Brett
    Hello; I am new to Objective C, and am trying to write a class that defines a complex number. The code seems fine but when I print to the console, my values for instance variables are 0. Here is the code: // // ComplexNumber.h // Mandelbrot Set // // Created by Brett on 10-06-02. // Copyright 2010 __MyCompanyName__. All rights reserved. // #import <Foundation/Foundation.h> #import <stdio.h> @interface ComplexNumber : NSObject { double real; double imaginary; } // Getters -(double) real; -(double) imaginary; // Setters -(void)setReal: (double) a andImaginary: (double) b; //Function -(ComplexNumber *)squared; @end // // ComplexNumber.m // Mandelbrot Set // // Created by Brett on 10-06-02. // Copyright 2010 __MyCompanyName__. All rights reserved. // #import "ComplexNumber.h" #import <math.h> #import <stdio.h> @implementation ComplexNumber -(double)real{ return self->real; } -(double)imaginary{ return self->imaginary; } -(void)setReal: (double) a andImaginary: (double) b{ self->real=a; self->imaginary=b; } -(ComplexNumber *)squared{ double a = pow(real,2); double b = pow(imaginary, 2); double c = 2*real*imaginary; ComplexNumber *d; [d setReal:(a-b) andImaginary: c]; return d; } @end In the App Delegate for debugging purposes I added: - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { ComplexNumber *testNumber = [[ComplexNumber alloc] init]; [testNumber setReal:55.0 andImaginary:30.0]; NSLog(@"%d", testNumber.real); // Override point for customization after app launch [window addSubview:viewController.view]; [window makeKeyAndVisible]; return YES; } But the console returns 0 everytime. Help?

    Read the article

  • How do I create a class in Javascript?

    - by William
    This is what I got so far, and it's not working at all :( <!DOCTYPE html> <html lang="en"> <head> <title>Class Test</title> <meta charset="utf-8" /> <style> body { text-align: center; background-color: #ffffff;} #box { position: absolute; left: 610px; top: 80px; height: 50px; width: 50px; background-color: #ff0000; color: #000000;} </style> <script type="text/javascript"> document.onkeydown=function(event){keyDown(event)}; document.onkeyup=function(event){keyUp(event)}; var box = 0; function Player () { var speed = 5; var x = 50; var y = 50; } function update() { box.style.left = this.x + "px"; box.style.top = this.y + "px"; box.innerHTML = "<h6 style=\"margin: 0px 0px 0px 0px; padding: 0px 0px 0px 0px;\">X: "+ this.x + "<br /> Y: " + this.y + "</h6>"; } var player = new Player(); var keys = new Array(256); var i = 0; for (i = 0;i <= 256; i++){ keys[i] = false; } function keyDown(event){ keys[event.keyCode] = true; } function keyUp(event){ keys[event.keyCode] = false; } function update(){ if(keys[37]) player.x -= player.speed; if(keys[39]) player.x += player.speed; player.update(); } setInterval(update, 1000/60); </script> </head> <body> <div id="box" ></div> <script type="text/javascript"> box = document.getElementById('box'); box.innerHTML = "<h6 style=\"margin: 0px 0px 0px 0px; padding: 0px 0px 0px 0px;\">X: "+ player.x + "<br /> Y: " + player.y + "</h6>"; </script> </body> </html>

    Read the article

  • Cutting down repeating code in c# Class

    - by Tom Gullen
    This is a wrapper for an API I'm working on, am I doing it sort of right? I'm not particularly fond of all the repeating code in the constructor, if someone can show me if I can reduce that it would be very helpful! public class WebWizForumVersion { // Properties of returned data public string Software { get; private set; } public string Version { get; private set; } public string APIVersion { get; private set; } public string Copyright { get; private set; } public string BoardName { get; private set; } public string URL { get; private set; } public string Email { get; private set; } public string Database { get; private set; } public string InstallationID { get; private set; } public bool NewsPad { get; private set; } public string NewsPadURL { get; private set; } public WebWizForumVersion(XmlReader Data) { try { Data.ReadToFollowing("Software"); this.Software = Data.ReadElementContentAsString(); Data.ReadToFollowing("Version"); this.Version = Data.ReadElementContentAsString(); Data.ReadToFollowing("ApiVersion"); this.APIVersion = Data.ReadElementContentAsString(); Data.ReadToFollowing("Copyright"); this.Copyright = Data.ReadElementContentAsString(); Data.ReadToFollowing("BoardName"); this.BoardName = Data.ReadElementContentAsString(); Data.ReadToFollowing("URL"); this.URL = Data.ReadElementContentAsString(); Data.ReadToFollowing("Email"); this.Email = Data.ReadElementContentAsString(); Data.ReadToFollowing("Database"); this.Database = Data.ReadElementContentAsString(); Data.ReadToFollowing("InstallID"); this.InstallationID = Data.ReadElementContentAsString(); Data.ReadToFollowing("NewsPad"); this.NewsPad = bool.Parse(Data.ReadElementContentAsString()); Data.ReadToFollowing("NewsPadURL"); this.NewsPadURL = Data.ReadElementContentAsString(); } catch (Exception e) { } } }

    Read the article

  • Super class variables not printing through sub class

    - by Abhishek Singh
    Can u tell me why this code is not displaying any result on the console. class employee { protected String name; protected double salary; protected String dob; public employee(String name, double salary, String dob) { this.name = name; this.salary = salary; this.dob = dob; } public employee(String name, double salary) { this.name = name; this.salary = salary; } } public class Manage extends employee { String dept1; public Manage(String name, double salary, String dob, String dept1) { super(name, salary, dob); this.dept1 = dept1; } public Manage(String name, double salary, String dept1) { super(name, salary); this.dept1 = dept1; } public static void main(String args[]) { employee e = new employee("Vikas", 122345); employee e2 = new employee("Vikas", 122345, "12-2-1991"); Manage m = (Manage) new Manage("Vikas", 122345, "Sales"); Manage m2 = new Manage("Vikas", 122345, "12-2-1991", "sales"); m.display(); m2.display(); } public void display() { System.out.println("Name " + name); System.out.println("Salary " + salary); System.out.println("Birth " + dob); System.out.println("Department " + dept1); } }

    Read the article

  • How to achieve interaction between GUI class with logic class

    - by volting
    Im new to GUI programming, and haven't done much OOP. Im working on a basic calculator app to help me learn GUI design and to brush up on OOP. I understand that anything GUI related should be kept seperate from the logic, but Im unsure how to implement interaction between logic an GUI classes when needed i.e. basically passing variables back and forth... Im using TKinter and when I pass a tkinter variable to my logic it only seems to hold the string PY_VAR0. def on_equal_btn_click(self): self.entryVariable.set(self.entryVariable.get() + "=") calculator = Calc(self.entryVariable) self.entryVariable.set(calculator.calculate()) Im sure that im probably doing something fundamentally wrong and probabaly really stupid, I spent a considerable amount of time experimenting (and searching for answers online) but Im getting no where. Any help would be appreciated. Thanks, V The Full Program (well just enough to show the structure..) import Tkinter class Gui(Tkinter.Tk): def __init__(self,parent): Tkinter.Tk.__init__(self,parent) self.parent = parent self.initialize() def initialize(self): self.grid() self.create_widgets() """ grid config """ #self.grid_columnconfigure(0,weight=1,pad=0) self.resizable(False, False) def create_widgets(self): """row 0 of grid""" """Create Text Entry Box""" self.entryVariable = Tkinter.StringVar() self.entry = Tkinter.Entry(self,width=30,textvariable=self.entryVariable) self.entry.grid(column=0,row=0, columnspan = 3 ) self.entry.bind("<Return>", self.on_press_enter) """create equal button""" equal_btn = Tkinter.Button(self,text="=",width=4,command=self.on_equal_btn_click) equal_btn.grid(column=3, row=0) """row 1 of grid""" """create number 1 button""" number1_btn = Tkinter.Button(self,text="1",width=8,command=self.on_number1_btn_click) number1_btn.grid(column=0, row=1) . . . def on_equal_btn_click(self): self.entryVariable.set(self.entryVariable.get() + "=") calculator = Calc(self.entryVariable) self.entryVariable.set(calculator.calculate()) class Calc(): def __init__(self, equation): self.equation = equation def calculate(self): #TODO: parse string and calculate... return self.equation if __name__ == "__main__": app = Gui(None) app.title('Calculator') app.mainloop()

    Read the article

  • Cast base class object to derived class

    - by Popgalop
    Lets say I have two classes, animal and dog like this. class Animal { }; class Dog : public Animal { }; And I have an animal object named animal, that is actually an instance of dog, how would I cast it back to dog? This may seem like an odd question, but I need it because I am writing a programming language interpreter, and on the stack everything is stored as a BaseObject, and all the other datatypes extend BaseObject. How would I cast the base object from the stack, to a specific data type? I have tried something like this Dog dog = static_cast<Dog>(animal); But it gives me an error 1>------ Build started: Project: StackTests, Configuration: Debug Win32 ------ 1> StackTests.cpp 1>c:\users\owner\documents\visual studio 2012\projects\stacktests\stacktests\stacktests.cpp(173): error C2440: 'static_cast' : cannot convert from 'Animal' to 'Dog' 1> No constructor could take the source type, or constructor overload resolution was ambiguous 1>c:\users\owner\documents\visual studio 2012\projects\stacktests\stacktests\stacktests.cpp(173): error C2512: 'Dog' : no appropriate default constructor available ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

    Read the article

  • Identifying a class which is extending an abstract class

    - by Simon A. Eugster
    Good Evening, I'm doing a major refactoring of http://wiki2xhtml.sourceforge.net/ to finally get better overview and maintainability. (I started the project when I decided to start programming, so – you get it, right? ;)) At the moment I wonder how to solve the problem I'll describe now: Every file will be put through several parsers (like one for links, one for tables, one for images, etc.): public class WikiLinks extends WikiTask { ... } public class WikiTables extends WikiTask { ... } The files will then be parsed about this way: public void parse() { if (!parse) return; WikiTask task = new WikiLinks(); do { task.parse(this); } while ((task = task.nextTask()) != null); } Sometimes I may want to use no parser at all (for files that only need to be copied), or only a chosen one (e.g. for testing purposes). So before running task.parse() I need to check whether this certain parser is actually necessary/desired. (Perhaps via Blacklist or Whitelist.) What would you suggest for comparing? An ID for each WikiTask (how to do?)? Comparing the task Object itself against a new instance of a WikiTask (overhead)?

    Read the article

  • Calling a class method within a method definition in the same class

    - by user1786288
    So I'm writing a program for an intro Java class. I'm defining a method to add two fractions together within the class Fraction. Fraction has 2 variables, numerator and denominator. Each of these variables has a setter and a getter. Anyway, I have a problem with my addition method, which is shown below. I've just sort of tried to implement it in a way that made sense, but I'm sure I did something with calling methods/using objects that doesn't work. public void add(Fraction fraction1, Fraction fraction2) { Fraction fraction3 = new Fraction(); int a = fraction1.getNumerator; int b = fraction1.getDenominator; int c = fraction2.getNumerator; int d = fraction2.getDenominator; fraction3.setNumerator((a * d) + (b * c)); fraction3.setDenominator(b * d); } I don't know if the problem is in the method definition, if I can use the object type that way, or if there's something else wrong. any help would be appreciated, and if I need to provide any information, I'll do so ASAP.

    Read the article

  • Override ToString() in your Classes

    - by psheriff
    One of the reasons I love teaching is because of the questions that I get from attendees. I was giving a presentation at DevConnections and was showing a collection of Product objects. When I hovered over the variable that contained the collection, it looked like Figure 2. As you can see in the collection, I have actual product names of my videos from www.pdsa.com/videos being displayed. To get your data to appear in the data tips you must override the ToString() method in your class. To illustrate this, take the following simple Product class shown below: public class Product{  public string ProductName { get; set; }  public int ProductId { get; set; }} This class does not have an override of the ToString() method so if you create a collection of Product objects you will end up with data tips that look like Figure 1. Below is the code I used to create a collection of Product objects. I have shortened the code in this blog, but you can get the full source code for this sample by following the instructions at the bottom of this blog entry. List<Product> coll = new List<Product>();Product prod; prod = new Product()  { ProductName = "From Zero to HTML 5 in 60 Minutes",     ProductId = 1 };coll.Add(prod);prod = new Product()   { ProductName = "Architecting Applications …",     ProductId = 2 };coll.Add(prod);prod = new Product()  { ProductName = "Introduction to Windows Phone Development",    ProductId = 3 };coll.Add(prod);prod = new Product()   { ProductName = "Architecting a Business  …",     ProductId = 4 };coll.Add(prod);......   Figure 1: Class without overriding ToString() Now, go back to the Product class and add an override of the ToString() method as shown in the code listed below: public class Product{  public string ProductName { get; set; }  public int ProductId { get; set; }   public override string ToString()  {    return ProductName;  }} In this simple sample, I am just returning the ProductName property. However, you can create a whole string of information if you wish to display more data in your data tips. Just concatenate any properties you want from your class and return that string. When you now run the application and hover over the collection object you will now see something that looks like Figure 2. Figure 2: Overriding ToString() in your Class Another place the ToString() override comes in handy is if you forget to use a DisplayMemberPath in your ListBox or ComboBox. The ToString() method is called automatically when a class is bound to a list control. Summary You should always override the ToString() method in your classes as this will help you when debugging your application. Seeing relevant data immediately in the data tip without having to drill down one more layer and maybe scroll through a complete list of properties should help speed up your development process. NOTE: You can download the sample code for this article by visiting my website at http://www.pdsa.com/downloads. Select “Tips & Tricks”, then select “Override ToString” from the drop down list.  

    Read the article

  • What's safe to assume about the NSMutableArray / NSArray class cluster?

    - by andyvn22
    I know you shouldn't use this to decide whether or not to change an array: if ([possiblyMutable isKindOfClass:[NSMutableArray class]]) But say I'm writing a method and need to return either an NSMutableArray or an NSArray, depending on the mutability of possiblyMutable. The class using my method already knows whether or not it's acceptable to change the returned array. Whether or not it's acceptable to change the returned array directly correlates with whether or not it's acceptable to change possiblyMutable. In that specific case, is this code safe? It seems to me that if it's not acceptable to change the array, but we accidentally get a mutable array, it's ok, because the class using my method won't try to change it. And if it is acceptable to change the array, then we will always get possiblyMutable as an NSMutableArray (though this is the part I'm not entirely clear on). So... safe or not? Alternatives?

    Read the article

  • C++ 2d Array Class Function Call Help

    - by johnny-conrad
    I hope this question takes a simple fix, and I am just missing something very small. I am in my second semester of C++ in college, and we are just getting into OOP. This is my first OOP program, and it is causing me a little problem. Here are the errors I am getting: Member function must be called or its address taken in function displayGrid(int,Cell ( *)[20]) Member function must be called or its address taken in function Turn(int,int,Cell ( *)[20]) Member function must be called or its address taken in function Turn(int,int,Cell ( *)[20]) Warning: Parameter 'grid' is never used in function displayGrid(int,Cell ( *)[20]) Here is all of my code. I am aware It is much more code than necessary, sorry if it makes it more difficult. I was worried that I might accidentally delete something. const int MAX=20; //Struct Cell holds player and their symbol. class Cell { private: int Player; char Symbol; public: Cell(void); void setPlayer(int); void setSymbol(char); int getPlayer(void); char getSymbol(void); }; Cell::Cell(void) { Symbol ='-'; } void Cell::setPlayer(int player_num) { Player = player_num; } void Cell::setSymbol(char rps) { Symbol = rps; } int Cell::getPlayer(void) { return Player; } char Cell::getSymbol(void) { return Symbol; } void Turn(int, int, Cell[MAX][MAX]); void displayGrid(int, Cell[MAX][MAX]); void main(void) { int size; cout << "How big would you like the grid to be: "; cin >> size; //Checks to see valid grid size while(size>MAX || size<3) { cout << "Grid size must between 20 and 3." << endl; cout << "Please re-enter the grid size: "; cin >> size; } int cnt=1; int full; Cell grid[MAX][MAX]; //I use full to detect when the game is over by squaring size. full = size*size; cout << "Starting a new game." << endl; //Exits loop when cnt reaches full. while(cnt<full+1) { displayGrid(size, grid); //calls function to display grid if(cnt%2==0) //if cnt is even then it's 2nd players turn cout << "Player 2's turn." << endl; else cout << "Player 1's turn" << endl; Turn(size, cnt, grid); //calls Turn do each players turn cnt++; } cout << endl; cout << "Board is full... Game Over" << endl; } void displayGrid(int size, Cell grid[MAX][MAX]) { cout << endl; cout << " "; for(int x=1; x<size+1; x++) // prints first row cout << setw(3) << x; // of numbers. cout << endl; //Nested-For prints the grid. for(int i=1; i<size+1; i++) { cout << setw(2) << i; for(int c=1; c<size+1; c++) { cout << setw(3) << grid[i][c].getSymbol; } cout << endl; } cout << endl; } void Turn(int size, int cnt, Cell grid[MAX][MAX]) { char temp; char choice; int row=0; int column=0; cout << "Enter the Row: "; cin >> row; cout << "Enter the Column: "; cin >> column; //puts what is in the current cell in "temp" temp = grid[row][column].getSymbol; //Checks to see if temp is occupied or not while(temp!='-') { cout << "Cell space is Occupied..." << endl; cout << "Enter the Row: "; cin >> row; cout << "Enter the Column: "; cin >> column; temp = grid[row][column].getSymbol; //exits loop when finally correct } if(cnt%2==0) //if cnt is even then its player 2's turn { cout << "Enter your Symbol R, P, or S (Capitals): "; cin >> choice; grid[row][column].setPlayer(1); in >> choice; } //officially sets choice to grid cell grid[row][column].setSymbol(choice); } else //if cnt is odd then its player 1's turn { cout << "Enter your Symbol r, p, or s (Lower-Case): "; cin >> choice; grid[row][column].setPlayer(2); //checks for valid input by user1 while(choice!= 'r' && choice!='p' && choice!='s') { cout << "Invalid Symbol... Please Re-Enter: "; cin >> choice; } //officially sets choice to grid cell. grid[row][column].setSymbol(choice); } cout << endl; } Thanks alot for your help!

    Read the article

  • Why is TDD not working here?

    - by TobiMcNamobi
    I want to write a class A that has a method calculate(<params>). That method should calculate a value using database data. So I wrote a class Test_A for unit testing (TDD). The database access is done using another class which I have mocked with a class, let's call it Accessor_Mockup. Now, the TDD cycle requires me to add a test that fails and make the simplest changes to A so that the test passes. So I add data to Accessor_Mockup and call A.calculate with appropriate parameters. But why should A use the accessor class at all? It would be simpler (!) if the class just "knows" the values it could retrieve from the database. For every test I write I could introduce such a new value (or an if-branch or whatever). But wait ... TDD is more. There is the refactoring part. But that sounds to me like "OK, I can do this all with a big if-elseif construct. I could refactor it using a new class ... but instead I make use of the DB accessor and do this in a totally different way. The code will not necessarily look better afterwards but I know I WANT to use the database".

    Read the article

  • C++ Class Templates (Queue of a class)

    - by Dalton Conley
    Ok, so I have my basic linked Queue class with basic functions such as front(), empty() etc.. and I have transformed it into a template. Now, I also have a class called Student. Which holds 2 values: Student name and Student Id. I can print out a student with the following code.. Student me("My Name", 2); cout << me << endl; Here is my display function for student: void display(ostream &out) const { out << "Student Name: " << name << "\tStudent Id: " << id << "\tAddress: " << this << endl; } Now it works fine, you can see the basic output. Now I'm declaring a queue like so.. Queue<Student> qstu; Storing data in this queue is fine, I can add new values and such.. now what I'm trying to do is print out my whole queue of students with: cout << qstu << endl; But its simply returning an address.. here is my display function for queues. void display(ostream & out) const { NodePointer ptr; ptr = myFront; while(ptr != NULL) { out << ptr->data << " "; ptr = ptr->next; } out << endl; } Now, based on this, I assume ptr-data is a Student type and I would assume this would work, but it doesn't. Is there something I'm missing? Also, when I Try: ptr->data.display(out); (Making the assumtion ptr-data is of type student, it does not work which tells me I am doing something wrong. Help on this would be much appreciated!

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 32 33 34 35 36 37 38 39 40 41 42 43  | Next Page >