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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24
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5answers
1k views

Saving an object via a method of its own or via another class?

If I want to save and retrieve an object. Should I create another class to handle it, or it's better to do that within the class? Or maybe mixing of both? Which is recommended according to OOD ...
2
votes
3answers
401 views

Class design - should methods call other methods?

I'm writing a very basic custom class for coupons and I've come up with a basic layout for the class, which consists of a number of small methods as I generally understand is a best practice. What ...
0
votes
1answer
68 views

How to organize conversion logic for strategy pattern?

I have a Color class. It has a property model which is a class that implements ColorModel interface, this property could be a RGB, Hex or HSL classes which implementing ColorModel interface. // ...
6
votes
1answer
288 views

In MVC should a model contain subview models?

Some background: A colleague and myself have different interpretations of MVC which means, given the same problem, we are coming up with radically different solutions. He comes from a Java background ...
2
votes
3answers
184 views

Getters and Setters unclear example

I know autmatic getters and setters are considers bad as they tend to break object's encapsulation. They also move the work that should have been done within the object outside. Allen Holub is a big ...
1
vote
1answer
340 views

Creating a calendar/planner program. Confused about OO logic?

I'd like to create a piece of software that has the functionality of a common written planner. To do this, it will have a Calendar. When planning the program, I became confused as to how I would ...
1
vote
1answer
223 views

Alan Kay: “The Big Idea is Messaging” [duplicate]

Alan Kay said "OO" was about messaging, not objects and drew a parallel to biological cells. His views are enticing, but vague. The way I understand it is something like a Cellular Automata. In a ...
1
vote
3answers
364 views

Building a calculator using MVC

I've been programming in Java for about 6 months, and I thought a good and challenging test of my skills would be to build a GUI calculator. I have very recently heard about this MVC idea, and I ...
5
votes
3answers
269 views

How to handle a memory consuming member variable

Suppose multiple objects of the same class should do something which takes a memory consuming resource. Which of the following approaches is recommended to define and use the resource by the objects? ...
4
votes
1answer
114 views

Extend, wrap, or both to add generics to a class that should have had them?

So I'm using a C# framework that has a great example of where generics would be useful, except they weren't used. For simplicity's sake, we will say it was a list (I know C# has its own list), but ...
1
vote
3answers
224 views

Member variables vs. State Varaibels? Are they the same? [closed]

I am learning that member variables are to hold the state of an object? Is it their recommended usage? Are all member variables state variables too? or state variables have specific definition and ...
3
votes
1answer
149 views

Usage of this keyword in constructor chaining?

I am reading msdn documentation for this keyword. They gave three usages for this keyword as follows To qualify members hidden by similar names To pass an object as a parameter to other methods To ...
0
votes
1answer
119 views

Should I use a class as a wrapper?

Lets say I have a class representing a chemical compound class Compound(networkx.Graph): def __init__(self): super(Compound, self).__init__() And lets say that I want to add some ...
0
votes
1answer
128 views

Intermediate results as variables or only base values?

I have a object which has a few base variables (integers as example) and one intermediate variable for further processing. The intermediate variable can be calculated from the base vars. Now the ...
1
vote
1answer
58 views

Do the implementations of the Node interface in Web API violate Liskov Substitution Principle?

MDN article on Node interface states that interfaces [that inherit from Node interface] may return null in particular cases where the methods and properties are not relevant. They may throw an ...
3
votes
1answer
139 views

Why 'JButton' is-a 'Container' in javax.swing?

As per the class hierarchy in java.awt.*, class Button & class Label is-a class Component, and Component is not a Container, which make sense to me. As per the redesign of class hierarchy in ...
-1
votes
2answers
83 views

what is the difference between inclusion and inheritance [duplicate]

the question is self explanatory, I just want to know when to use the inclusion and when to use inheritance, and which one serves for re-usability. in other words, which one meets the Object ...
1
vote
2answers
85 views

Query on Recursive composition

For the below relation between Container and Componentin java.awt class hierarchy, I see that, in addition to is-a relation, class Container has composite relation with class Component with below ...
0
votes
1answer
81 views

Does class Availability makes programming as Object Oriented Language? [duplicate]

Does class Availability makes programming as Object Oriented Language ? Most of the people think that if there is Availability Class in a language, then that language becomes Object Oriented. Is it ...
1
vote
3answers
117 views

Exposition of Data Representation

I would like to know how the data representation is exposed in slide 7 of information hiding: Modifying an exposed data representation propagates to all code which directly accesses that ...
0
votes
2answers
205 views

if a c# interface contain only getter and setter definition, is it a code smell?

A project that I am working on has the following code for interface example: using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace Test { public ...
0
votes
1answer
107 views

Coupling in OOP Contracts: Many simple values of few complex objects as arguments?

When designing an OOP-based application, should one prefer to transfer information between objects through complex objects that do a lot of handling work, or should I retrieve the data from the ...
0
votes
2answers
276 views

Bad Practice using Auto Generated Classes for Data Access

I've seen this before but haven't found concrete reasons. When you add Entities to your EF model, EF auto generates classes for these entities. In terms of DataAccess, why is it preferred to not ...
-1
votes
3answers
148 views

Objects in smalltalk and c++ [closed]

I have a question based on SmallTalk and C++. In one of the programming languages books, there is a question like: "Does an object in Smalltalk require its own private stack? What about in C++?" ...
0
votes
3answers
2k views

I want to understand clearly why can't we instantiate an object of an abstract class [duplicate]

Can I get a clear explanation why why can't we instantiate an object of an abstract class. I know abstract is not real. But I want to know more why can't we instantiate an object of an abstract class. ...
0
votes
3answers
133 views

Communicating between unrelated components/objects

Imagine that I have a game, with Monsters, Missions, Vehicles, and of course their controllers and such, so a Monster class, Mission Controller class, Vehicle Controller class and so on. Suppose that ...
2
votes
1answer
293 views

Convert procedural code to object oriented

I have a PHP application (a web service). It consists of files grouped in directories by theme like :      /customer         /search.php with this example content : Auth::authenticate($options); ...
1
vote
2answers
141 views

Python: Object initialised inside a Class?

Is possible and, if so, common practice to initialize an object inside a class in Python? self.field = Class()
1
vote
1answer
291 views

Inheritance, Composition and Protocols

I'm reading a book on general object oriented concepts to try and gain a solid understanding of everything. One thing that is throwing me off is the difference between Inheritance and Composition. I ...
1
vote
1answer
194 views

Should we use data object (or the data transfer object) for sharing data between these three classes?

I found an article by Martin Fowler that has made me doubt my design choices, particularly about data objects. Martin Fowler has written an article about what he thinks is a code smell. In this ...
0
votes
3answers
652 views

Force Derived Class to Implement Static Method C#

So the situation is like, I have few classes, all of which have a standard CRUD methods but static. I want to create a base class which will be inherited so that it can force to implement this CRUD ...
1
vote
1answer
103 views

Setting fields of a base class when using the constructor is not an option

I am refactoring a base class, implementations of which are plug-ins, loaded at runtime by another class using reflection. The class I am refactoring uses a user ID of the form domain\user. I need ...
2
votes
2answers
58 views

How to ORM non-disjoint specializations

Consider this highly simplified sample of relational data (each table may be involved in one-to-many and many-to-many relationships not shown here): people +-------+------+--------+ | name | born | ...
2
votes
2answers
90 views

Domain/Model objects attributes good practices

Simple question: Should model/domain objects only include attributes that are meant to be persisted in a database or serialized to any other specific format? My understanding of a domain/model object ...
3
votes
3answers
759 views

Should we add constructors to structs

We often use c++ structs to define data structure as opposed to class which can be a complete module with member methods. Now deep down, we know they both are the same (loosely speaking). The fact ...
3
votes
1answer
165 views

Advantages and drawbacks of different ways using Either-types

I am writing software for compiling programs. Therefore have a Compiler that compiles a given sourcecode. It then returns a CompileResult that is similiar to an Either type (it is actually internally ...
13
votes
10answers
2k views

Can objects constructed from the same class have unique method definitions?

I know this seems like a weird question, since the point of two or more objects sharing the same class is that their behavior is the same, i.e. their methods are identical. However, I'm curious if ...
3
votes
2answers
167 views

OOP CLI menu structure organization?

This problem has kept me from pursuing a project I'm working on because it influences the entire structure of the application. This question has been briefly touched on here, but I feel that it wasn't ...
2
votes
1answer
141 views

Should I use composition or inheritance for sharing configuration items?

I'm working on a fairly new project where I'd like to share some config items used by a JavaScript plugin. Specifically, the project is using jQuery dataTables and I want to find a good way of sharing ...
1
vote
2answers
105 views

Is composition and aggregation really a type of association relationship?

From Wikipedia: There are four different types of association: bi-directional, uni-directional, Aggregation (includes Composition aggregation) and Reflexive. From what I know: Composition ...
1
vote
2answers
154 views

Cleanest choice for symmetric operations

I have a need to do some processing from a format A to a format B and from B to A. The job in one direction is very similar to its counterpart. Both formats are represented with an interface Msg. In ...
-1
votes
1answer
48 views

How do Event Bus and ReativeX interact with each other?

I wanted to look into communication/decoupling patterns and how to improve them. My current approach is to have a centralized commander in the form of an Event Bus and make him be the one to respond ...
0
votes
3answers
122 views

OOP: relying on protected properties in a class-subclass contract

I'm coding in Python, but the question seems independent of programming language. I have a class that represents some system check: class Check: @abstractmethod def run() """ You have to ...
-2
votes
1answer
64 views

Naming of classes [closed]

I am creating an Email sending client. My POJO domain model conssts of 2 string fields, userName and userId. My thought process around designing the classes was to club these 2 fields into a domain ...
4
votes
2answers
859 views

What is the difference between Encapsulation and High cohesion?

I've looked at encapsulation and cohesion, but they look like the same thing to me. Isn't an encapsulated object already highly-cohesive?
-2
votes
1answer
91 views

Architecture - 3D Modeling Library

I'm writing a library to allow users to generate 3D models programatically. User writes code (e.g. Square(4)) User views preview of 3D model (with built in visualizer) User can "print" the model to ...
2
votes
2answers
389 views

Generics in low level languages

I'm developing a language like Vala and OOC that compiles back to C. This means that, eventually, every feature needs to be adoptable to C code in some way or another. Generics is one of the features ...
2
votes
3answers
304 views

Inheritance in imperative programming

My first introduction to programming was Java, which was horrible so I learnt Actionscript3 which was nice... "The point is" OOP was my introduction to programming where by I went on to gain a career ...
3
votes
3answers
249 views

Interface to enumerate over files

I'm trying to design a generic interface for enumerating over a list files. Each iteration will open a file, allow the consuming code to access the file to perform some task, and then close the file. ...
2
votes
4answers
222 views

Determining a class structure

I'm currently in the early stages of designing an e-commerce application. I'm working out some designs for my classes which have so far been fairly straightforward, but I've run into something of a ...