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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1answer
199 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
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3answers
239 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
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2answers
199 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
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1answer
101 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
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4answers
221 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
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1answer
144 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
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1answer
115 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
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1answer
113 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
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1answer
54 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
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1answer
115 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
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2answers
76 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
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2answers
69 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
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1answer
78 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
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3answers
114 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
186 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
103 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
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2answers
229 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
144 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
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3answers
439 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
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3answers
118 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
256 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
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2answers
136 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
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1answer
173 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
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1answer
180 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
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3answers
435 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
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1answer
94 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
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2answers
82 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
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3answers
434 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
111 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
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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
138 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
132 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
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2answers
98 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 ...
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2answers
150 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 ...
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1answer
42 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
118 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 ...
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votes
1answer
63 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
769 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?
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votes
1answer
88 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
380 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
283 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
235 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
218 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 ...
0
votes
3answers
161 views

Why static members can't be abstract and don't implement polymorphism? [duplicate]

I'm a Java/C#/PHP developer, through my OOP programming experience I find myself asking the same question: Why static members can't be abstract and don't implement polymorphism especially in ...
1
vote
1answer
205 views

Should I couple these classes?

I am programming in Python. I have several complicated/hard-to-understand XML files that describe the structure of an election. I am trying to write a python wrapper that makes it easy to access this ...
0
votes
1answer
142 views

What should be in a PIMPL?

I am kinda trying to implement a windowing library in C++, the circumstances are forcing me to implement it all myself, that's not the point of this question however. My question is: What should be ...
3
votes
1answer
88 views

Design Question - System Integration

Guidance on good application architecture / design is not in short supply however most of the examples focus on some business object, like Customer and its behaviour and persistence. There is little ...
0
votes
1answer
189 views

Is not being able to resolve a function call to its declaration a drawback of Polymorphism?

Consider a class that prints an "outline" table for a particular product line. Say you have several, A, B, C, D. The mechanism of the table generation is the same, but the data is different. I ...
1
vote
1answer
240 views

Designing classes the right way [closed]

I am trying to design my classes in the optimal way for the following scenario. A city has metro lines covering a number of stations.There are 4 lines represented by 4 colors.The user has to enter ...