Search Results

Search found 3956 results on 159 pages for 'constructor overloading'.

Page 104/159 | < Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >

  • How can I pass methods in javascript?

    - by peterjwest
    I often need to pass methods from objects into other objects. However I usually want the method to be attached to the original object (by attached I mean 'this' should refer to the original object). I know a few ways to do this: a) In the object constructor: ObjectA = function() { var that = this; var method = function(a,b,c) { that.abc = a+b+c }} b) In objectA which has been passed objectB: objectB.assign(function(a,b,c) { that.method(a,b,c) }) c) Outside both objects: objectB.assign(function(a,b,c) { objectA.method(a,b,c) }) I want to know if there is a simpler way to pass methods attached to their original objects.

    Read the article

  • defining a simple implicit Arbitary

    - by FredOverflow
    I have a type Foo with a constructor that takes an Int. How do I define an implicit Arbitrary for Foo to be used with scalacheck? implicit def arbFoo: Arbitrary[Foo] = ??? I came up with the following solution, but it's a bit too "manual" and low-level for my taste: val fooGen = for (i <- Gen.choose(Int.MinValue, Int.MaxValue)) yield new Foo(i) implicit def arbFoo: Arbitrary[Foo] = Arbitrary(fooGen) Ideally, I would want a higher-order function where I just have to plug in an Int => Foo function. I managed to cut it down to: implicit def arbFoo = Arbitrary(Gen.resultOf((i: Int) => new Foo(i))) But I still feel like there has got to be a slightly simpler way.

    Read the article

  • More elegant way to make a C++ member function change different member variables based on template p

    - by Eric Moyer
    Today, I wrote some code that needed to add elements to different container variables depending on the type of a template parameter. I solved it by writing a friend helper class specialized on its own template parameter which had a member variable of the original class. It saved me a few hundred lines of repeating myself without adding much complexity. However, it seemed kludgey. I would like to know if there is a better, more elegant way. The code below is a greatly simplified example illustrating the problem and my solution. It compiles in g++. #include <vector> #include <algorithm> #include <iostream> namespace myNS{ template<class Elt> struct Container{ std::vector<Elt> contents; template<class Iter> void set(Iter begin, Iter end){ contents.erase(contents.begin(), contents.end()); std::copy(begin, end, back_inserter(contents)); } }; struct User; namespace WkNS{ template<class Elt> struct Worker{ User& u; Worker(User& u):u(u){} template<class Iter> void set(Iter begin, Iter end); }; }; struct F{ int x; explicit F(int x):x(x){} }; struct G{ double x; explicit G(double x):x(x){} }; struct User{ Container<F> a; Container<G> b; template<class Elt> void doIt(Elt x, Elt y){ std::vector<Elt> v; v.push_back(x); v.push_back(y); Worker<Elt>(*this).set(v.begin(), v.end()); } }; namespace WkNS{ template<class Elt> template<class Iter> void Worker<Elt>::set(Iter begin, Iter end){ std::cout << "Set a." << std::endl; u.a.set(begin, end); } template<> template<class Iter> void Worker<G>::set(Iter begin, Iter end){ std::cout << "Set b." << std::endl; u.b.set(begin, end); } }; }; int main(){ using myNS::F; using myNS::G; myNS::User u; u.doIt(F(1),F(2)); u.doIt(G(3),G(4)); } User is the class I was writing. Worker is my helper class. I have it in its own namespace because I don't want it causing trouble outside myNS. Container is a container class whose definition I don't want to modify, but is used by User in its instance variables. doIt<F> should modify a. doIt<G> should modify b. F and G are open to limited modification if that would produce a more elegant solution. (As an example of one such modification, in the real application F's constructor takes a dummy parameter to make it look like G's constructor and save me from repeating myself.) In the real code, Worker is a friend of User and member variables are private. To make the example simpler to write, I made everything public. However, a solution that requires things to be public really doesn't answer my question. Given all these caveats, is there a better way to write User::doIt?

    Read the article

  • How can I add a field with an array value to my Perl object?

    - by superstar
    What's the difference between these two constructors in perl? 1) sub new { my $class = shift; my $self = {}; $self->{firstName} = undef; $self->{lastName} = undef; $self->{PEERS} = []; bless ($self, $class); return $self; } 2) sub new { my $class = shift; my $self = { _firstName => shift, _lastName => shift, _ssn => shift, }; bless $self, $class; return $self; } I am using the second one so far, but I need to implement the PEERS array in the second one? How do I do it with the second constructor and how can we use get and set methods on those array variables?

    Read the article

  • WxWidgets custom events

    - by Klaus
    Hello, I'm trying to use a custom event in my WxWidgets C++ application, like described here. In the constructor of my wxApp: Connect(wxID_ANY, wxCommandEventHandler(APP::OnMyEvent)); Then the function that should catch the event: void APP::OnMyEvent(wxCommandEvent& event) { exit(0); //testing } Finally, to test it: wxCommandEvent MyEvent(wxEVT_COMMAND_BUTTON_CLICKED); wxPostEvent(this, MyEvent); I launch the thing...but it seems that the event is not posted or not caught. Does someone understand this behaviour ?

    Read the article

  • How to model dependency injection in UML ?

    - by hjo1620
    I have a Contract class. The contract is valid 1 Jan 2010 - 31 Dec 2010. It can be in state Active or Passive, depending on which date I ask the instance for it's state. ex. if I ask 4 July 2010, it's in state Active, but if I ask 1 Jan 2011, it's in state Passive. Instances are created using constructor dependency injection, i.e. they are either Active or Passive already when created, null is not allowed as a parameter for the internal state member. One initial/created vertex is drawn in UML. I have two arrows, leading out from the initial vertex, one leading to state Active and the other to state Passive. Is this a correct representation of dependency injection in UML ? This is related to http://stackoverflow.com/questions/2779922/how-model-statemachine-when-state-is-dependent-on-a-function which initiated the question on how to model DI in general, in UML.

    Read the article

  • Accessing a Clip Inside Another Clip in a Loaded SWF-File

    - by Anders
    I'm writing a card game in AS3. The artist I'm working with has produced (in Flash CS4) a single swf-file containing all the card graphics and animations. The structure of the fla working file looks something like this: - Scene - CardGraphics (Movie Clip) - CardFront - CardBack - CardValueImage (Movie Clip) ... In the program I create 52 instances of my Card class, each having a MovieClip instance created from the loaded swf. The idea is to set the frame of the CardValueImage MovieClip to correspond to the Card instance's suit and rank member variables. However, I can't figure out how I access CardValueImage and call gotoAndStop (or whatever method I will need to call). This is basically what I want to do: // Card Class [Embed(source = 'CardGraphics.swf')] private static var CardsClip:Class; private var clip:MovieClip = new CardsClip; // Card Constructor this.valueImageFrame = suit * 13 + rank; // Calculate which frame contains the // graphical representation of this card this.clip.CardValueImage.gotoAndStop(valueImageFrame);

    Read the article

  • Are we using IoC effectively?

    - by Juliet
    So my company uses Castle Windsor IoC container, but in a way that feels "off": All the data types are registered in code, not the config file. All data types are hard-coded to use one interface implementation. In fact, for nearly all given interfaces, there is and will only ever be one implementation. All registered data types have a default constructor, so Windsor doesn't instantiate an object graph for any registered types. The people who designed the system insist the IoC container makes the system better. We have 1200+ public classes, so its a big system, the kind where you'd expect to find a framework like Windsor. But I'm still skeptical. Is my company using IoC effectively? Is there an advantage to new'ing objects with Windsor than new'ing objects with the new keyword?

    Read the article

  • AutoMapper and Linq expression.

    - by Raffaeu
    I am exposing the Dto generated from AutoMapper to my WCF services. I would like to offer something like that from WCF: IList GetPersonByQuery(Expression predicate); Unfortunately I need back an expression tree of Person as my DAL doesn't know the DTO. I am trying this wihtout success: var func = new Func<Person, bool>(x => x.FirstName.Contains("John")); var funcDto = Mapper.Map<Func<Person, bool>, Func<PersonDto, bool>>(func); Console.WriteLine(func.ToString()); Console.WriteLine(funcDto.ToString()); THe error that I get is: ----> System.ArgumentException : Type 'System.Func`2[TestAutoMapper.PersonDto,System.Boolean]' does not have a default constructor Do you have any suggestions?

    Read the article

  • different explanation

    - by Delirium tremens
    The following code echoes 5, not 10: $global_obj = null; class my_class { var $value; function my_class() { global $global_obj; $global_obj = &$this; } } $a = new my_class; $a->my_value = 5; $global_obj->my_value = 10; echo $a->my_value; "Upon first examination, it would seem that the constructor of my_class stores a reference to itself inside the $global_obj variable. Therefore, one would expect that, when we later change the value of $global_obj-my_value to 10, the corresponding value in $a would change as well. Unfortunately, the new operator does not return a reference, but a copy of the newly created object." Please, give me a different explanation.

    Read the article

  • Ruby on Rails: building a model with an attribute not in the database?

    - by randombits
    I have a model that sets one of its attributes based off of a form parameter that a user submits. The model is a child resource to a parent resource Home. A hypothetical example is the following: A class Person has an age attribute. The user submits a birthdate as an HTTP POST parameter and from that, I need to derive the age of the user. So I'd do something like this: @home.people.build(:name => params[:name], :birthdate => params[:birthdate]) Rails would barf on that for obvious reasons, complaining it doesn't know what the attribute birthdate is. What's the proper way of going about this? Is it possible to use the build constructor with the supplied solution so that my foreign key relations are also setup properly? If not, what's a better way to work around this problem?

    Read the article

  • How to set default values to the properties of dynamically loaded types at runtime for XML serializa

    - by Erkan Y.
    I need to serialize dynamically loaded types' classes using XMLSerializer. When using XML serializer non initialized values are not being serialized. I dont have control over the assemblies I am working with so can not use XML attributes for specifying default values on properties. So I think I need to set all properties and sub properties to their default values recursively and then serialize. ( Please let me know if there is any better way ) Followed this : Activator.CreateInstance(propType); but above line complains about not having a parameterless constructor for some types. Tried this : subObject = FormatterServices.GetUninitializedObject(propType); but this one gives an error "value was invalid" with no inner exception. Please let me know if you need any further information.

    Read the article

  • How can I access and modify objects inside frames with AS3 in a permanent way?

    - by curro
    I have a MovieClip symbol created with flash in a fla file library. There is a textfield in frame one of this movieclip's timeline . There is another frame in the movieclip timeline. There is a custon class definition for this symbol. It is a flipping card in a memory game. I access the textfield by going to frame 2 (gotoAndStop(2)) and setting the textfield's text property ( this.field.text = "hello" ). However if I go to frame 1 and then return to frame 2, the text becomes the original one in the library's symbol. I have to modify the text propery again in a showFace method I've written. Besides, I cannot pass parameters in the constructor because it is a symbol in the library and that would give errors. I find this behaviour of flash extremely weird. Is there a way I can set properties inside frames permanently? Thank you

    Read the article

  • Can there be two public section in a class? If yes then why ? And in which circumstances we do so?

    - by Abhi
    Dear all I have a doubt related to class. For example class A { public: A() { ..... ..... } void cleanup() { .... .... .... } public: UINT a; ULONG b; }; In the above example there are two public section, In first section i am defining constructor and the method and in the second section i am declaring data members. Does the above class i.e. A is correct. Can we do so? If yes then why we needed and in which circumstances we should use it? Also we can do the entire thing in one section then why un necessary we r taking two section...? Thanks and regards Abhineet Agarwal

    Read the article

  • Relvance of 'public' contructor in abstract class.

    - by Amby
    Is there any relevance of a 'public' constructor in an abstract class? I can not think of any possible way to use it, in that case shouldn't it be treated as error by compiler (C#, not sure if other languages allow that). Sample Code: internal abstract class Vehicle { public Vehicle() { } } The C# compiler allows this code to compile, while there is no way i can call this contructor from the outside world. It can be called from derived classes only. So shouldn't it allow 'protected' and 'private' modifiers only. Please comment.

    Read the article

  • Can anyone recommend a .Net XML Serialization library?

    - by James
    Can anyone recommend a .Net XML Serialization library (ideally open source). I am looking for a robust XML serialization library that I can throw any object at, which will produce a human readable XML representation of the public properties for logging purposes. I never need to be able to deserialize. XmlSerializer's requirement of an object having a parameter constructor is too restrictive for what I want. DataContractSerializer does not give enough control over the output (which is not particularly human-readable). Any recommendations appreciated! Thanks

    Read the article

  • my .jar file won't do anything.

    - by David
    I created a program that more or less holds an array of strings as an object and randomly prints one. so basicaly class Happy { string[] namestrings = new string[#] constructor() { fill with some strings} public static void main (String[]arg) { create instance of class do some junk with it method that prints it } method that prints it {} another method } when i compile and run it on the command line it works fine but when on the comand line i type in jar -cf Happy.jar Fun.class i get a .jar file called Happy and when i click on it i get an error message that reads "the java Jar file happy could not be launched read the consol for possible error messages" I have a mac i'm running lepord if that makes a diference. Whats going on?

    Read the article

  • C# property in a form class only accessable after formload event

    - by Spooky2010
    using vs2008, c# Howdy, Im instantiating and calling Form B from Form A. FormB has some custom properties, to allow me to pass it things like sqlAdaptors and dataset instances. When i instantiate and show Form B from Form A as a dialog form with a Using statement, it all works fine, but i find the properties i pass are not available in Form B until after the form_load event has fired. I was under the impression the properties when passed to a instantiated class should be available from a constructor, but this is not the case. If it try to access the properties before the form load event i get a null reference exception. Is this correct behavior ? It is very annoying. thanks for any help

    Read the article

  • Android and Google Maps API - Icons

    - by oriharel
    I want to place markers on the map. I want to use the standard Google Maps icons for markers. how do I use them? I don't want to create my own icons. I'm developing for Android. in the documentation they tell me to create a class that overrides ItemizedOverlay but in the constructor I'm asked to provide a drawable object. how do I point to the standard Google Maps ones? thanks.

    Read the article

  • 2 Classes need each other declared C++

    - by Prodigga
    I have a "Game" class which holds all the games settings and manages the game. I have a "Grid" class which is the grid the game is played on. The "Game" class initializes a "Grid" object as one of its members (passing itself ("this") as one of the parameters for "Grid"s constructor).. The "Grid" object therefor needs to deal with a "Game*" pointer. To do this it needs to know what "Game" is; i need to declare it before "Grid". But "Game" uses "Grid"...so it also needs "Grid" declared before it. so confused on how to include headers/etc correctly here..

    Read the article

  • Implementing implicitly shared classes outside of Qt

    - by Timothy Baldridge
    I'm familiar with the way Qt uses D-pointers for managing data. How do I do this in my code? I tried this method: 1) move all data into a struct 2) add a QAtomicInt to the struct 3) implement a = operator and change my constructor/deconstructor to check-up on the reference count. The issue is, when I go to do a shallow copy of the object, I get an error about QObject declaring = as private. How then do I accomplish this? Here's an example of my copy operator: HttpRequest & HttpRequest::operator=(const HttpRequest &other) { other.d->ref.ref(); if (!d->ref.deref()) delete d; d = other.d; return *this; } Am I going about this the wrong way?

    Read the article

  • Doubt in abstract classes

    - by mohit
    public abstract class Person { private String name; public Person(String name) { this.name = name; System.out.println("Person"); } public String getName() { return name; } abstract public String getDescription(); } public class Student extends Person { private String major; public Student(String name, String major) { super(name); this.major = major; } public String getMajor() { return major; } @Override public String getDescription() { return "student" + super.getName() + " having" + major; } } public class PersonTest { public static void main(String[] args) { Person person = new Student("XYZ", "ABC"); System.out.println(person.getDescription()); } } Ques: We cannot create objects of abstract classes, then why Person Constructor has been invoked, even its an abstract class?

    Read the article

  • android java.lang.OutOfMemoryError

    - by xiangdream
    hi, all, when i download large data from website, i got this error information: I/global (20094): Default buffer size used in BufferedInputStream constructor. It would be better to be explicit if an 8k buffer is required. D/dalvikvm(20094): GC freed 6153 objects / 3650840 bytes in 335ms I/dalvikvm-heap(20094): Forcing collection of SoftReferences for 3599051-byte al location D/dalvikvm(20094): GC freed 320 objects / 11400 bytes in 144ms E/dalvikvm-heap(20094): Out of memory on a 3599051-byte allocation. I/dalvikvm(20094): "Thread-9" prio=5 tid=17 RUNNABLE I/dalvikvm(20094): | group="main" sCount=0 dsCount=0 s=0 obj=0x439b9480 I/dalvikvm(20094): | sysTid=25762 nice=0 sched=0/0 handle=4065496 anyone can help me?

    Read the article

  • extension method phone format with country code as parameter

    - by frenchie
    Hi, I'm writing an extension method called ToPhoneFormat that formats a string of digits to phone numbers. Is it possible to add a parameter to the method that would enable me to call it like this: MyPhoneString.ToPhoneFormat(international code) That way, I could write MyPhoneString.ToPhoneFormat(1); to format a US phone number and MyPhoneString.ToPhoneFormat(33) to format a French phone number. I already wrote the method that does the formatting but I'm wondering how to build the constructor so that it works with a parameter when I'm calling it. Thanks.

    Read the article

  • Singletons and other design issues

    - by Ahmed Saleh
    I have worked using different languages like C++/Java and currently AS3. Most applications were computer vision, and small 2D computer games. Most companies that I have worked for, they use Singletons in a language like AS3, to retrieve elements or classes in an easy way. Their problem is basically they needs some variables or to call other functions from other classes. In a language like AS3, there is no private constructor, and they write a hacky code to prevent new instances. In Java and C++ I also faced the situation that I need to use other classe's members or to call their functions in different classes. The question is, is there a better or another design, to let other classes interact with each others without using singletons? I feel that composition is the answer, but I need more detailed solutions or design suggestions.

    Read the article

< Previous Page | 100 101 102 103 104 105 106 107 108 109 110 111  | Next Page >