oop

How to explain to someone that a data structure should not draw itself, explaining separation of concerns?

I have another programmer who I'm trying to explain why it is that a UI component should not also be a data-structure. For instance say that you get a data-structure that contains a record-set from the "database", and you wish to display that record-set in a UI component within your application. According to this programmer (who will...

How to manage data access / preloading efficiently using web services in C# ?

Hello all, Ok, this is very "generic" question. We currently have a SQL Server database for which we need to develop an application in ASP.NET with will contain all the business logic in C# Web Services. The thing is that, architecturally speaking, I'm not sure how to design the web service and the data management. There are many th...

example for Singleton pattern

Hi, Please give me a real time example for singleton pattern . Different threads accessing a shared file is singleton or not ? Since each thread access the same instance of the file not individual instances of their own . ...

Objective-C Objects Having Each Other as Properties

Let's say we have two objects. Furthermore, let's assume that they really have no reason to exist without each other. So we aren't too worried about re-usability. Is there anything wrong with them "knowing about" each other? Meaning, can each one have the other as a property? Is it OK to do something like this in a mythical third c...

Can I have two names for the same variable?

The short version of the question: I do: x = y. Then I change x, and y is unchanged. What I want is to "bind" x and y in such a way that I change y whenever I change x. The extended version (with some details): I wrote a class ("first" class) which generates objects of another class ("second" class). In more details, every object of t...

Confuse about which object should i assign the function to

i have the following two class which convert object into xml string should i do something like class Person { public string GetXml() { //return a xml string } } or it is better to create another class which accept the person as a parameter and convert it into XML something like class PersonSerializer { ...

What is the right way to implement communication between java objects?

I'm working on an academic project which simulates a rather large queuing procedure in java. The core of the simulator rests within one package where there exist 8 classes, each one implementing a single concept. Every class in the project follows SRP. These classes encapsulate the behavior of the simulator and inter-connect every other ...

Is it a oop good design ?

Hi all, I'd like to know what you think about this part of our program is realized : We have in our database a list of campsite. Partners call us to get all the campsites near a GPS location or all the campsites which provide a bar (we call it a service). So how I realized it ? Here is our database : Campsite - ID - NAME - GPS_lat...

How to "wrap" implementation in C#

Hello, I have these classes in C# (.NET Framework 3.5) described below: public class Base { public int State {get; set;} public virtual int Method1(){} public virtual string Method2(){} ... public virtual void Method10(){} } public class B: Base { // some implementation } public class Proxy: Base { private B _...

PHP Access property of a class from within a class instantiated in the original class.

I'm not certain how to explain this with the correct terms so maybe an example is the best method... $master = new MasterClass(); $master->doStuff(); class MasterClass { var $a; var $b; var $c; var $eventProccer; function MasterClass() { $this->a = 1; $this->eventProccer = new EventProcess();...

constructors and inheritance in JS

Hi all, This is about "inheritance" in JavaScript. Supose I create a constructor Bird(), and another called Parrot() which I make to "inherit" the props of Bird by asigning an instance of it to Parrot's prototype, like the following code shows: function Bird() { this.fly = function(){}; } function Parrot() { this.talk = funct...

Is it a good object-oriented-design practice to send a pointer to private data to another class?

Hello everyone, There is well known recommendation not to include into class interface method that returns a pointer (or a reference) to private data of the class. But what do you think about method of a class that sends to another class a pointer to the private data of the first one. For example: class A { public: void fA...

which metric(s) show the difference between object-oriented and procedural code

Which metric(s) could help to indicate that i have procedural code instead of object-oriented code? I would like to have a set of simple metrics, which indicate with a high probability, that the analyzed code contains procedural transaction scripts and an anemic domain model instead of following sound object-oriented design principles. ...

Why implement DB connection pointer object as a reference counting pointer? (C++)

At our company one of the core C++ classes (Database connection pointer) is implemented as a reference counting pointer. To be clear, the objects are NOT DB connections themselves, but pointers to a DB connection object. The library is very old, and nobody who designed is around anymore. So far, nether I, nor any C++ experts in the co...

Creating instance of interface in C#

I'm working with MS Excel interop in C# and I don't understand how this particular line of code works: var excel = new Microsoft.Office.Interop.Excel.Application(); where Microsoft.Office.Interop.Excel.Application is an INTERFACE defined as: [Guid("000208D5-0000-0000-C000-000000000046")] [CoClass(typeof(ApplicationClass))] public int...

SQL constructs translated to OOP

As someone who comes from the world of Object Orientation, I find it rather difficult to wrap my head around SQL. Recently, however, I realized that the classical SQL construct select X from Y where Z is basically equivalent to the following OOP construct: List<SomeType> results = db.query(new Matcher<SomeType> () { public boolean ...

Use of base class object by child class reference - java

Hi, What is the use of creating base class object using child class reference in Java ...

Do I correctly understand what a class is?

I've had trouble finding a clear, concise laymans definition of a class. Usually, they give general ideas without specifically spelling it out, and I'm wondering if I'm understanding this correctly. As I understand it, a class is the set of code that controls an object. For example, in an app that has a button for 'Yes' and a button for ...

What objects would get defined in a Bridge scoring app (Javascript)

I'm writing a Bridge (card game) scoring application as practice in javascript, and am looking for suggestions on how to set up my objects. I'm pretty new to OO in general, and would love a survey of how and why people would structure a program to do this (the "survey" begets the CW mark. Additionally, I'll happily close this if it's out...

What is Encapsulation and how can it defend abstractions against corruption?

It's quoted from a report by Bjarne: Encapsulation – the ability to provide guarantees that an abstraction is used only according to its specification – is crucial to defend abstractions against corruption. Can someone explain this? Thanks ...