A methodology that enables a system to be modeled as a set of objects that can be controlled and manipulated in a modular manner

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3
votes
4answers
227 views

From the perspective of OOP, taking performance into account - should a database connection be a static field, an instance field, or a local variable?

When methods use a database connection, should the connection be a static field, an instance field, or a local variable? Here are my doubts. I dithered which are correct and which are baseless. I ...
0
votes
2answers
244 views

Don't auto-implemented properties violate encapsulation?

In C#, when a field getting or setting requires logic, we use properties. For example: private int _age; public int Age { get { Console.Writeline("Club member is {0} years old", _age);...
1
vote
3answers
99 views

Xml Messages: One Type to Rule Them All?

My job involves a project that has a lot of different pieces that all need to communicate via XML messages. There are two schools of thought on how these messages should be organized. In reality ...
46
votes
10answers
6k views

Should we avoid custom objects as parameters?

Suppose I have a custom object, Student: public class Student{ public int _id; public String name; public int age; public float score; } And a class, Window, that is used to show ...
2
votes
1answer
127 views

Fine tuning details in C++ function for different customers

The company I work for follows a business model where a core product exists (originally written in C, now in C++) with some default implementation but details are tailor-made for each customer (there ...
5
votes
6answers
615 views

How much do function calls impact performance?

Extracting functionality into methods or functions is a must for code modularity, readability and interoperability, especially in OOP. But this means more functions calls will be made. How does ...
-1
votes
1answer
150 views

What is the faster way to save and browse objects using vectors +/or maps? (c++)

I'm doing a object Garbage class using c++: #include "Object.h" class ObjectGarbage { public: ObjectGarbage(); ~ObjectGarbage(); void Call_All_Objects() { //(...
7
votes
3answers
244 views

Using Interfaces for Loosely Coupled Code

Background I have a project that depends on the usage of a certain type of hardware device, while it doesn't really matter who makes that hardware device as long as it does what I need it to do. With ...
0
votes
1answer
111 views

How to call an unknown member function through an instance of a related class?

I have two classes. The first, called Game_Events, controls the objects and manages the general tasks. The second, called Button, is for one of those object instances. The example below is wrong but ...
4
votes
2answers
262 views

Why is an abstract class forced to define all functions of an inherited interface?

Why does c# compiler force an abstract class to define (as opposed to implement) all the methods of the inherited interface ? why does it not mark unimplemented methods of an inherited interface as ...
1
vote
2answers
36 views

Are Data defined into derived class saved when up-casting?

Let's say i have two class named Object (base class) and an actor class (derived class). The actor class uses physics so i need to implement it on the Actor class. But there are other derived class of ...
1
vote
1answer
16 views

In what sense does the complexity of class hierarchies motivated by static type checking?

For example, from the book JavaScript: The Good Parts, I stumbled upon this passage: Much of the complexity of class hierarchies is motivated by the constraints of static type checking. ...
-4
votes
2answers
54 views

Cache repository violating the SRP [closed]

interface IRepository { Data getData(); } class BaseRepository implements IRepository { public Data getData() { ... } } class CacheRepository implements IRepository { private final ...
35
votes
5answers
3k views

When should I extend a Java Swing class?

My current understanding of Inheritance implementation is that one should only extend a class if an IS-A relation is present. If the parent class can further have more specific child types with ...
1
vote
1answer
45 views

How to use fields from an object after an exception is thrown and the object can't be fully created

The issue that I have is that I need information from an object that a method returns when it throws an exception. It is a little hard to describe so I have this java pseudo code example. I have a ...
1
vote
0answers
31 views

How to Make Reusable Classes/Package in Laravel for Billing which uses PaymentExpress?

I am working on a Laravel Project where we are Payment Express. What currently we are doing is that we have Payment Express Class with static function (Not a single property) like given below: Class ...
6
votes
1answer
443 views

How to make clear that a method can be overridden?

I have a library that I use in several applications. It has a method that returns a URL: class UrlBuilder { public function url($config) { $config = do_some_checks($config); return make_url(...
5
votes
3answers
216 views

Is it ever appropriate to use subtyping for a has-a relationship?

One of the basic precepts of object oriented programming is that subtyping represents the "is-a" relationship. That is, the child is always a specific form of the parent. A common example is that a ...
1
vote
1answer
72 views

In a .NET Windows Forms app with a custom MVC, should a custom UserControl (view) implement any non-animating logic on its own?

This is strongly linked to these two questions: http://stackoverflow.com/q/15800945/279112 Should Controller know about View & Model? or vice versa? as well as this one: http://codereview....
3
votes
1answer
166 views

Checking preconditions the proper way

I have a class with around 1300 lines and it has many CRUD-like methods that need parameters to be checked, for some of them it's more than just a few rules. For clarity purposes, I am going to use ...
4
votes
3answers
141 views

Who is responsible for checking object properties such as Visible/Enabled?

Say we have a user interface with Forms, Buttons and such. Each item has some properties (such as Visible, Enabled, etc.). Who should check on these properties and decide whenever to render the item ...
3
votes
1answer
227 views

How to pass data to OOP objects?

I'm new to this whole thing, so please tell me if I'm doing this wrong of if there's a better spot for my question. I'm making a game with basic systems for projectiles, npcs and items. This game ...
1
vote
0answers
45 views

Why Does JavaFX's GridPane Attach Properties of the Layout to the Components?

I am currently learning JavaFX and I came across a very strange API for laying out GUI components. It is perhaps best explained by it's javadoc: To use the GridPane, an application needs to set ...
9
votes
3answers
283 views

OOP design problem. Two kinds of empty Optional

I'm writing a quite simple application that deals with hotel rooms reservation. I've got a problem at one stage. I'm processing a queue of orders. For every order one of the receptionists should ...
3
votes
5answers
202 views

What is the correct OOP relation between complex and real numbers?

On one hand class complex { double real; double imaginary; } it is composition on the other hand class complex : double { double imaginary; } it is inheritance Which one is ...
-1
votes
1answer
43 views

algorithm to convert technical specification into object model [closed]

I have detailed specification of what should my program take as input, and give as output. How to convert this specification into classes/methods/properties? I used such algorithm: Take ...
1
vote
1answer
51 views

Redesigning a builder to make it reusable

Let's say I have a builder class (which by the way is not techinically a builder, but it's not a factory either) to generate different rules for a game: public class RuleBuilder { private Game ...
-1
votes
2answers
107 views

Do you say “this” on protected members? [closed]

Background I have never had a formal class in OOP/OOD although I understand how the protected members work. Being accessible by any instance/derived class, they are thereby less private (more ...
13
votes
4answers
1k views

How specific should the Single Responsibility pattern be for classes?

For example, suppose you have a console game program, which has all kinds of input/output methods to and from the console. Would it be smart to keep them all in a single inputOutput class or break ...
2
votes
2answers
91 views

How to handle when only certain derived classes need to be disposed?

I am trying to build a framework of objects where the main actors can be interchanged freely. At the moment I've done this by creating an abstract base class that all of my actors can be derived from. ...
1
vote
1answer
182 views

OOP: how to keep some state for a brief moment?

My job and my personal interests often have me writing parsing code, that is, code that converts from an input string written in a given formal language to a tree of model objects. I come from a C ...
1
vote
3answers
95 views

Implementing an event scheduler for animations

The basic idea is to have some animated widgets that sit in a container, quite similar to Qt (the only actual difference is that my widgets are animated). The animation is in some cases dependent on ...
0
votes
1answer
142 views

What would be the merits/disadvantages of an OOP language that forced the generator pattern?

In OOP languages, programs can define static methods that can generate objects with different parameters (including subclassed or pre-generated objects), but they are not as commonly used because we ...
3
votes
3answers
97 views

Ways to structure a program with 2 states

I'm working on some sort of a Level Editor but I'm not quite sure how I want to handle the two different states: The Editor state and the Player state. In this first state game elements can be moved ...
0
votes
1answer
95 views

Passing a Serial Port Instance

Background I am thinking about designing a (GoF/behavioral) command-pattern interface. I may decide to call this thing ICommand. I am thinking that I would have some sort of a queue containing a ...
5
votes
3answers
115 views

Understanding Multiple Dispatch

I've been reading around trying to understand multiple dispatching, and why it's so special. On Wikipedia I came across this simple example: (defmethod collide-with ((x asteroid) (y asteroid)) ;;...
1
vote
1answer
133 views

Returning functions within Javascript objects

After coming across Douglas Crockford's views on class-free OOP, and doing away with new and this in Javascript I tried defining an object with its own variable and function, and returning it in a ...
0
votes
1answer
132 views

Question(s) about PHP PDO connections

Let's say I have a Db class [ db.php ] : <?php class Db { // class properties private $db_driver = ''; // dsn credentials private $db_dhost = ''; private $...
24
votes
7answers
3k views

How to return warnings alongside result of calculation to caller of a Java method? [duplicate]

I have a class, lets call it Calculator, with a method like this: public double[] performCalculation(double[] someInData) This method can generate a number of non fatal warnings (represented as an ...
1
vote
0answers
113 views

Making code more “modular”

As an semi-experienced procedural PHP developer, my OOP still needs a lot of work. I am still working through SOLID principles and other theories and guidelines of OOP, and am stuck with something ...
0
votes
2answers
73 views

What are 'good' cases for subtype overloads

To explain what I mean, I'm going to give an example of a bad case for a subtype overload. Let's say we have a community of people. And depending on what kind people are in our community, our ...
27
votes
5answers
5k views

Is overriding concrete methods a code smell?

Is it true that overriding concrete methods is a code smell? Because I think if you need to override concrete methods: public class A{ public void a(){ } } public class B extends A{ @...
4
votes
4answers
297 views

Should an object be able to represent itself across components?

I'm working on a networked game. I have tried to design the various components (client, server, engine) to only about things within their domain. For example, the server should only be concerned with ...
0
votes
1answer
92 views

Design Pattern for Object Updates

I have a "Product" class that has some ID, and multiple other fields, and a function updateProduct(id, Product update). The intention is that "update" only contains the changed information - other ...
-1
votes
3answers
176 views

Modularity vs Polymorphism (OOD main concepts)

Booch gives 4 main concepts (principles) of OOD (see his book Object-oriented analysis and design with applications ): Abstraction Encapsulation Modularity Hierarchy Usually we encounter to these ...
0
votes
2answers
256 views

Without using Singletons, what is a good way to manage a global resource? [duplicate]

Unlike many libraries SDL and OpenGL are designed to provide global resources; you can access them at any time from any class. There are justifications for this: They are written in C, meant to be ...
1
vote
1answer
104 views

Should “magic” getter functions be used for dynamically calculated values or just existing properties?

For example, if I had a Customer class and wanted to get all orders by them. Would it be better to do: class Customer{ public function getOrders(){ return results from db query } } .....
1
vote
4answers
260 views

Can the circle-ellipse problem be solved by reversing the relationship?

Having Circle extend Ellipse breaks the Liskov Substition Principle, because it modifies a postcondition: namely, you can set X and Y independently to draw an ellipse, but X must always equal Y for ...
-2
votes
3answers
180 views

Is it possible to have private or protected objects in Java? Or are all objects considered public?

Is it possible to have private objects? For example, when you instantiate an object (classType object1 = new classType()), can that be private or protected or is it always public?
0
votes
1answer
70 views

How do you write super() in the UML format?Is it correct to write super(parameter: type): return type in the UML methods section?

Suppose you write a subclass that extends to a certain class and in that subclass, you use the super() method for your constructor. Would you write "super(parameter: type): return type" in the UML?