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
1answer
110 views

Web Application: OOP or procedural

I'm building a Web Application that includes a search, user profiles, rating, gallery, comments, etc. While writing the outline I was not sure whether to do this by coding the functions directly in ...
9
votes
4answers
3k views

Can a C struct behave like it had a function?

I use C and structs where a struct can have members but not functions. Assume for simplicity that I want to create a struct for strings that I name str and I want to be able to do str.replace(int i, ...
5
votes
5answers
245 views

Do you generally send objects or their member variables into functions?

Which is generally accepted practice between these two cases: function insertIntoDatabase(Account account, Otherthing thing) { database.insertMethod(account.getId(), thing.getId(), ...
5
votes
1answer
201 views

Why does this shared buffer work?

Background The following code snippet is taken from a problem in, Visual C# 2005: How to Program, by Paul and Harvey Deitel (pp. 735). The code snippet is more or less an application for accessing ...
13
votes
4answers
2k views

When to use inheritance, when to use 'just a boolean field'?

In our Rails application, we are adding notifications. Some of these are blocking: They stop the progress of whatever resource they are added on, because some information on that resource is missing. ...
2
votes
2answers
116 views

Placing preconditions in the right place

I am trying to figure out the best way to define the responsibility of checking preconditions. Let's consider the following case: we have an Event class representing a sports event and a Matchup ...
0
votes
0answers
27 views

I am trying to make a function with that returns true/false if an element is in the vector but I am getting an error? [migrated]

I am trying to implement a function in C++ using STL which takes an object and a vector of objects and return true if the vector contains the object else false. Below is the implementation of the ...
1
vote
4answers
198 views

Why do I need to declare virtual functions as such?

Example: We have a base class Base and three subclasses which all implement their own version of doSomething(). In an intermediate function f(Base b), we want to call the relevant version of ...
2
votes
2answers
80 views

C++ vs Java: Pointing to Objects

In Java: private State current_state; As "State" is a superclass, I can then assign subclass objects to current_state, effectively making current_state point to a different object: current_state = ...
3
votes
2answers
80 views

Creating Instances from same SuperClass Object

I have 3 subclasses (LowState, MediumState, HighState) which derive from the same superclass (State). Within the superclass, State, I have declared several variables which need to be accessed and ...
18
votes
6answers
2k views

Is it okay for interfaces to contain a method which returns the concrete type of the implementation in form of a constant?

I very often get myself in a situation where I need a different behavior of a component which depends on the concrete type of a different Interface. To illustrate my question, I have written a small ...
5
votes
3answers
135 views

Breaking large class into smaller classes when they need a common state?

I am writing a parser for a fairly complicated language in C++. The Parser class is given a list of tokens and it builds the AST. Though only a part of the parser is completed, the Parser.cpp file is ...
-1
votes
3answers
55 views

What do you call the two types of classes on a instance declaration

When you declare a new instance of a class, you do so in a lot of languages as: MyClass obj = new MyClass(); The two MyClass mean subtly different things, often you will see: IMyClass obj = new ...
-2
votes
2answers
168 views

OOP project design

here is the UML class diagram subscribe method is used to add a herbivore object to the plant's watchers. when a plant is told to notify, itloops through all of the herbivore object in its watchers ...
2
votes
2answers
169 views

How to avoid circular reference in OOP Javascript?

I have a problem while working with entity framework in JavaScript. I have two classes Table and Column Class Table { Columns: Column[] } Class Column { Parent: Table } Everything works fine until ...
4
votes
2answers
86 views

Serializing mutating objects

In our system a media file can have several states: invalid, empty, uploading, ingesting, ready… Depending of the state, information about the media are accessed in different ways. For example, during ...
1
vote
1answer
21 views

Redesigning schedule value hierarchy

I have a couple of schedule value classes that represent the value a schedule holds for a specific slot. First, there's the ScheduleValue class for schedules with two dimensions, where the first one ...
0
votes
3answers
157 views

Is data duplication bad in programming (in contrast to database designing)?

I have three classes: User, Conversation and Message: Message properties: User sender; // Some more Conversation properties: List<Message> messages; List<User> participants; // Some ...
3
votes
4answers
223 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 ...
-1
votes
1answer
67 views

Python Exception Handling in Def Function? [on hold]

I know that this is an elementary question as my misunderstanding is in the syntax and format of the coding. I'm learning, as we all are. So here's some Pyhton code: def SCounter(x): ...
0
votes
2answers
232 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", ...
1
vote
3answers
96 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 ...
44
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
121 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 ...
4
votes
6answers
555 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
149 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
215 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
108 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
236 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
15 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
53 views

Cache repository violating the SRP [closed]

interface IRepository { Data getData(); } class BaseRepository implements IRepository { public Data getData() { ... } } class CacheRepository implements IRepository { private final ...
34
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
44 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
21 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 ...
5
votes
3answers
213 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
64 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: ...
2
votes
1answer
145 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
215 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
37 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
274 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
193 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
40 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
48 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
102 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
89 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
181 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 ...