Object-oriented design is the process of planning a system of interacting objects for the purpose of solving a software problem.

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Is there a design pattern for managing deep many-to-many relationships?

I'm having trouble defining this data pattern I've come across working on several applications. It consists of: An object type which is composed of many objects itself A second object type, where ...
7
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4answers
836 views

Should Objects with lots of fields be broken up? [duplicate]

When I have an Object that has lots of fields is it better to have them all as fields or try to find logical groupings as their own Objects and make those the fields? I guess it comes down to which ...
0
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1answer
77 views

Should I put the parameters in constructor or in method? (Python 3)

I have the following code: def __init__(self, vocable_file_path, xsd_file_path, word_list_file_path): self.vocable_file_path = vocable_file_path self.xsd_file_path = xsd_file_path ...
3
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1answer
131 views

Should a new type be created though it only wraps a single field?

Say I have an interface Species that's defined as public interface Species { String getId(); String getDescription(); } The question is simply this: Should I create different classes to ...
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3answers
61 views

Deserializing an object at beginning of program which is used (much) later

I am writing a program, where in the beginning of the execution, I am instantiating a number of classifier objects using parameters stored in some files. I later use those classifiers in multiple ...
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3answers
282 views

'Encapsulation Vs Performance' trade-off in a lockable linked list

Main purpose of encapsulation is to protect in-variants of any class(in java). Here is the complete code for class DList/class lockDList/class DListNode/class LockDListNode. class DList and it's ...
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0answers
16 views

How should one model an ExchangeService object (in ews-java-api) for sharing MS Exchange connections?

I am creating an application which uses ews-java-api to connect to an MS Exchange server. Once the connection is authenticated, the api dictates use of ExchangeService object for searching mailboxes, ...
3
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3answers
352 views

Object creation: when should I expose a factory vs wrapping class?

I am having some problems trying to figure out when to use a factory or to wrapper class. This question is slightly geared towards C# I guess, so I'm not sure if this is the correct place to ask. Say ...
0
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1answer
65 views

How to better isolate JOGL or LWJGL3 dependency from game clients?

I'm currently working on a project to develop a relatively small framework with the goal of supporting game development efforts for students in a course. The scope of this project is an OpenGL-based ...
1
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2answers
108 views

Issues deciding on approach to create object

I'm trying to decide what's the best approach to instantiate a particular class. Basically there are two use cases for it: instantiate it in order to save a new entry to the database and fetch an ...
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4answers
206 views

OOP Principles in Customer and Account classes of a Bank

I am designing a Bank Application which deals with Customers having FD Accounts. There are two approaches to this : Approach 1 In this the customer has a list of accounts. The bank application ...
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3answers
124 views

How to understand if a property is a member of a class or I have to create a different class that holds it?

Sometimes when you create a class you can add there several properties (new data members) that you are not certain if you want to do or not. For example, I have a casino slots game. I have tiles and ...
2
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1answer
61 views

For DI, where to create dependencies (new objects) specifically within framework code?

Basic requirement I'm making a framework for learning purposes (and likely usage on personal sites). I'm using dependency injection in classes and I'm trying to design where would be a good place ...
2
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1answer
97 views

How to best model an application's settings?

My application has a configuration file and a "Settings" window. When the user confirms the changes in this window they are applied and written to the config file. These settings are often changed ...
1
vote
1answer
148 views

Private method with a derivable argument - a code smell?

We're implementing a service for creating a subscription where the subscription may be linked to an order. Quick background: the purpose of this service is to allow the customer to receive the item ...
0
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1answer
37 views

two repositories with kind of different behavior serving same object

I have a simple object like this public class Book { public List Chapters { get; private set; } public TableOfContent BookTOC { get; set; } public string Identifier { ...
2
votes
1answer
621 views

Interface questions for using Command Pattern and Dependency Injection together

I have many projects that have essentially the same high level requirement: test all hardware on a device. Each device can have a different communication protocol, requires different test equipment to ...
10
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5answers
513 views

Should I prefer composition or inheritance in this scenario?

Consider an interface: interface IWaveGenerator { SoundWave GenerateWave(double frequency, double lengthInSeconds); } This interface is implemented by a number of classes which generate waves ...
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4answers
337 views

How can I avoid the use of strings?

I'm implementing a program where the user can 'create a musical scale' from a variety of notes (identified by their names), and the program will generate music from this scale. I want to implement a ...
5
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1answer
129 views

Design pattern for data structure that contains at most one item of each type

I have a superinterface that several different abstract classes implement: Coverage. This is for insurance rating. There are several types of different coverage, and those coverages might vary by ...
2
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3answers
233 views

How to share data members between classes in C++ without violating encapsulation too much

In C++ let's say I have some class A: Class A { int a1, a2, a3; void foo(); } and I need to use a subset of members (a1, a2) in a member function for a second class B. ...
2
votes
2answers
143 views

OO Design Question - Library/Objects for API which includes id references

Public api: getClients / getClientById - returns a json object like: { clientid: 1, name: "Client1" } getProjects / getProjectById - returns a json object like { projectid: 5, name: ...
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2answers
139 views

User and role modeling

I'm working with a system in ASP.NET MVC, with Entity Framework for ORM. The application has a requirements to allow users to have different types of roles, and authorization rules will be different ...
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2answers
115 views

How should I structure these Python classes?

Base Class I have a class called Remote. This class represents a remote machine and has properties such as ip, hostname, username, and password, as well as methods for transferring files to/from the ...
2
votes
1answer
221 views

General design choices. How do you decide?

I have a project in C that I'm looking to convert to C++. The project does white box hardware testing of a device (actually many similar devices). In this case the device has two processors. Each ...
3
votes
2answers
186 views

Python classes with only one instance: When to create a (single) class instance and when to work with the class instead?

Given a Python class which will be instantiated only once, i.e. there will be only one object of the class. I was wondering in which cases it makes sense to create a single class instance instead of ...
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2answers
301 views

Updating an Entity through a Service

I'm separating my software into three main layers (maybe tiers would be a better term): Presentation ('Views') Business logic ('Services' and 'Repositories') Data access ('Entities' (e.g. ...
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3answers
169 views

How do I recreate this Access Control/Group/ whatever methodology in OO/MVC

I am looking at trying to rewrite an application that is mostly procedural to an MVC/OO approach in order to teach myself a deeper understanding of both. BUT, I am having some conceptual issues with ...
2
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2answers
657 views

Liskov substitution and abstract classes / strategy pattern

I'm trying to follow LSP in practical programming. And I wonder if different constructors of subclasses violate it. It would be great to hear an explanation instead of just yes/no. Thanks much! P.S. ...
0
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2answers
67 views

How to better define SRP and “wholesome” objects? [duplicate]

Assume you have a class. It can really be any class that defines a domain concept like an employee, a product on an e-commerce site, or a car. One of those examples that are oldies but goodies. ...
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0answers
40 views

EF “Code First” and Object/Relational Impedance

I'm trying to learn more about the current orthodoxy with respect to ASP.NET MVC application design, and I stumbled upon something that confuses me, relating to the choice among database design ...
3
votes
3answers
93 views

Is this a valid situation for returning rather than throwing an exception?

This is not something I would ever normally do, but I have a situation where some existing legacy code is being reused in a new application. The code is shared and needs to be used by both the legacy ...
2
votes
2answers
129 views

How to avoid god controller classes and keep single responsibility principle?

The task is to make a migrator from Old DB to New DB using OOP Single Responsibility Principle. My problem is how can I make this without making the controller a God Class or breaking the single ...
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3answers
265 views

“Correct” way to use inheritance

Within a small project, a class Storage is meant to store any type of Item. Now, an Item has a String name, and an interaction. For example, a clock item might implement the interaction increment(int ...
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3answers
271 views

How can I add properties to subclasses and access them without casting from a superclass?

I'm trying to model a multi-dimensional point class in C#. I have about eight different types of points, and there may be more in the future. Right now, I have a superclass (PointBase) that holds all ...
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votes
2answers
104 views

How to reference one object with two interfaces? [duplicate]

Suppose I have two interfaces I and J that is implemented by Test class. Now I need one object of class Test that is referenced by I and J both interfaces. I can do it by singleton design pattern. But ...
1
vote
1answer
134 views

Inefficient use of interfaces in OOP (C#)

In my code, I've got two interfaces, let's say IOpenable and IExaminable. IOpenable allows the user to Open or Close the object, and IExaminable allows the user to Examine the object. Now, we have ...
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5answers
267 views

OODesign: Data Structure which calls algorithm on insert

I have a data structure which has an add function. When the user instantiates a new data structure object, she can specify an algorithm which will be executed each time the add function is called and ...
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4answers
202 views

How to write procedural code in an object oriented language?

I recently started working in domain of mesh generation . My programs usually contains large chunks of procedural code consisting of several phases. Eg. class MeshAlgo1 { /* A very long function ...
4
votes
2answers
49 views

Is it acceptable to define a “module” and “class” within a single .VB element?

Experiment: I have found it is possible to define both a "Module" (Namespace?) and a "Class" (Namespace?) within a single .Vb element (Module??). You can try this at home: Create a new Console ...
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1answer
91 views

HashMap to replace Singletons?

Consider the following: I have controllers and views in a client-application. As this runs purely on the client side, each controller must only exist once. At first I thought about implementing ...
3
votes
2answers
85 views

COM - with great power comes great responsibility, but at what cost? (looking for advice on coding practices when working with COM)

What is best (or commonly accepted) practice for where to declare COM object variables (scope) and how to handle cleaning them up when using structured error handling? I just spend a whole load of ...
1
vote
1answer
44 views

How do you keep up with 'requiring new methods in an interface' (Following LSP and adding new methods to interface seems to violate ISP)

I have a game that deals with opening and closing doors and the Door Engine deals with IDoor interface which has Open() and Close() contracts So far so good. the game is tested and works fine. Now a ...
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3answers
149 views

What categories of software modeling problems is object orientation highly unsuitable for? [closed]

I'm trying to get a better grasp of the applicability of object-oriented programming and design. I'm curious about some examples of situations where object orientation is not simply inefficient or ...
10
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8answers
3k views

How do I design a subclass whose method contradicts its superclass? [duplicate]

How do I design a subclass whose method contradicts its superclass? Let's say we have this example: # Example 1 class Scissor def right_handed? true end end class LeftHandedScissor < ...
36
votes
8answers
3k views

Is OOP becoming easier or harder? [closed]

When the concepts of Object Oriented Programming were introduced to programmers years back it looks interesting and programming was cleaner. OOP was like this Stock stock = new Stock(); ...
2
votes
1answer
60 views

How to break mental model of objects

I've been working with OOP for a while now, but in each large project that I find myself starting, I seem to run into the same problem; where does the responsibility reside. Like many who use OOP on ...
0
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1answer
50 views

Use cases, User Stories, CRC cards and Conceptual Object Model

i'm currently in the middle of watching the Lynda.com course on the foundations of Object Oriented Design and one question keeps popping into my mind. When should I use Use cases and when should I ...
0
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1answer
70 views

Ways to avoid using switches to map strings to classes

I have a C# solution that reads records from a db and processes them into another db. The records to be processed are essentially one long string that represents the data and then another string ...
0
votes
1answer
170 views

How much to encapsulate when objects being dealt with are pretty similar

As I have been answering questions related to object-oriented design and how to go about reducing the amount of classes to make sure that there is not a lot of "class clutter" and code repetition I ...