constructor

How do I use an array as an object attribute in Perl?

Hello guys, I need some help regarding the arrays in Perl This is the constructor I have. BuildPacket.pm sub new { my $class = shift; my $Packet = { _PacketName => shift, _Platform => shift, _Version => shift, _IncludePath => [@_], ...

Overriding Constructors in F#

How would I write the following C# code in F#? namespace Shared { public class SharedRegistry : PageRegistry { public SharedRegistry(bool useCache = true) : base(useCache) { // Repositories ForRequestedType<IAddressRepository>().TheDefaultIsConcreteType<SqlAddressRepository>(); ...

Java - Should private instance variables be accessed in constructors through getters and setters method ?

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 th...

Object does not exist after constructor?

Hello, I have a constructor that looks like this (in c++): Interpreter::Interpreter() { tempDat == new DataObject(); tempDat->clear(); } the constructor of dataObject does absolutely nothing, and clear does this: bool DataObject::clear() { //clear the object if (current_max_id > 0) { inde...

C++, constructor restrictions

Hi everybaody, I'm studing C++ and I can't understand the meaning of the boldface sentence below: From IBM manual: The following restrictions apply to constructors and destructors: Constructors and destructors do not have return types nor can they return values. References and pointers cannot be used on constructors and de...

Java: How can a constructor return a value?

$ cat Const.java public class Const { String Const(String hello) { return hello; } public static void main(String[] args) { System.out.println(new Const("Hello!")); } } $ javac Const.java Const.java:7: cannot find symbol symbol : constructor Const(java.lang.String) location: class Const System.out.println(new Co...

How to access a control form from a constructor in another class

Hi, C# question: I have a textBox in a default form Form1 and I want to access (write on) it from a constructor in another class that is in another different file. How can I do it? Tx in advance, Gerard ...

Ctor not allowed return type.

Having code: struct B { int* a; B(int value):a(new int(value)) { } B():a(nullptr){} B(const B&); } B::B(const B& pattern) { } I'm getting err msg: 'Error 1 error C2533: 'B::{ctor}' : constructors not allowed a return type' Any idea why? P.S. I'm using VS 2010RC ...

Constructor return value

Could you tell me what is wrong with my class constructor? Code: CVector::CVector (int size_) { if (size_ > 0) { this->size = size_; this->data = new double[size]; for (int i = 0; i < size; i++) { (*this)(i) = i; } } cout << "constructor end" << endl; return; } Usage example: tvector = CVector(6); I get an access ...

Using an interface as a constructor parameter in Java?

How would I be able to accomplish the following: public class testClass implements Interface { public testClass(Interface[] args) { } } So that I could declare Interface testObject = new testClass(new class1(4), new class2(5)); Where class1 and class2 are also classes that implement Interface. Also, once I accomplish th...

Refactor throwing not null exception if using a method that has a dependency on a certain contructor

In the method below the second constructor accepts a ForumThread object which the IncrementViewCount() method uses. There is a dependency between the method and that particular constructor. Without extracting into a new private method the null check in IncrementViewCount() and LockForumThread() (plus other methods not shown) is there so...

What is the possible benefit (if any) of allowing recursive contructors?

In Java, constructors cannot be recursive. Compile time error: "recursive constructor invocation". Let's assume that we did not have this restriction. Things to keep in mind: The return type of a constructor is void. Since it is a void method you can't harness the complete power of recursion. A constructor can invoke itself (or any ot...

Can I have conditional construction of classes when using IoC.Resolve ?

I have a service class which has overloaded constructors. One constructor has 5 parameters and the other has 4. Before I call, var service = IoC.Resolve<IService>(); I want to do a test and based on the result of this test, resolve service using a specific constructor. In other words, bool testPassed = CheckCertainConditio...

Accessing the Private Constructor

I am java developer, went for an interview. I have been asked a question about the Private constructor 1) Can I access a Private Constructor of a Class and Instantiate the class. I was thinking and gave the answer directly--- "NO" But its wrong, can any one help Why NO? and How we can achieve this ...

How can one enforce calling a base class function after derived class constructor?

I'm looking for a clean C++ idiom for the following situation: class SomeLibraryClass { public: SomeLibraryClass() { /* start initialization */ } void addFoo() { /* we are a collection of foos */ } void funcToCallAfterAllAddFoos() { /* Making sure this is called is the issue */ } }; class SomeUserClass : public SomeLibrary...

Why would one want to use the public constructors on Boolean and similar immutable classes?

(For the purposes of this question, let us assume that one is intentionally not using auto(un)boxing, either because one is writing pre-Java 1.5 code, or because one feels that autounboxing makes it too easy to create NullPointerExceptions.) Take Boolean, for example. The documentation for the Boolean(boolean) constructor says: Note...

ArgumentError: Error #1063: Argument count mismatch on com.flashden::MenuItem(). Expected 1, got 0.

I keep getting the below error only in firefox ArgumentError: Error #1063: Argument count mismatch on com.flashden::MenuItem(). Expected 1, got 0. at flash.display::Sprite/constructChildren() at flash.display::Sprite() at flash.display::MovieClip() at com.flashden::Preview() Below is my menu script: package com.flashden { import ...

Strange constructor

Well, I'm gonna be pretty straightforward here, I just have a piece of code in c++ which I'm not sure I really understand and need some help with. Ok, to simplify lets just say I have a class that is defined like this: (the real class is a little bit more complicated, but this is what matters) class myClass : public Runnable { Sema...

I need an abstract field !

I know abstract fields do not exist in java. I also read this question but the solutions proposed won't solve my problem. Maybe there is no solution, but it's worth asking :) Problem I have an abstract class that does an operation in the constructor depending on the value of one of its fields. The problem is that the value of this fiel...

Is it possible to implement a C# constructor without using the class name?

When looking at disassembled .NET assemblies I notice that constructors are defined as ".ctor". Is that possible to do in the actual code? ...