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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Explanation on how “Tell, Don't Ask” is considered good OO

This blogpost was posted on Hacker News with several upvotes. Coming from C++, most of these examples seem to go against what I've been taught. Such as example #2: Bad: def ...
37
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6answers
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Should I create a class if my function is complex and has a lot of variables?

This question is somewhat language-agnostic, but not completely, since Object Oriented Programming (OOP) is different in, for example, Java, which doesn't have first-class functions, than it is in ...
36
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5answers
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Passing functions into other functions as parameters, bad practice?

We've been in the process of changing how our AS3 application talks to our back end and we're in the process of implementing a REST system to replace our old one. Sadly the developer who started the ...
36
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5answers
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How is defining that a method can be overridden a stronger commitment than defining that a method can be called?

From : http://www.artima.com/lejava/articles/designprinciples4.html Erich Gamma: I still think it's true even after ten years. Inheritance is a cool way to change behavior. But we know that it's ...
36
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11answers
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Constructor-only subclasses: Is this an anti-pattern?

I was having a discussion with a co-worker, and we ended up having conflicting intuitions about the purpose of subclassing. My intuition is that if a primary function of a subclass is to express a ...
36
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2answers
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Why do methods that take an unlimited amount of parameters often define overloads with fewer parameters?

For instance, the System.IO.Path.Combine method in .NET has the following overloads: Combine(params String[]) Combine(String, String) Combine(String, String, String) Combine(String, String, String, ...
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How are mixins or traits better than plain multiple inheritance?

C++ has plain multiple inheritance, many language designs forbid it as dangerous. But some languages like Ruby and PHP use strange syntax to do the same thing and call it mixins or traits. I heard ...
35
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2answers
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What are the advantages of prototype-based OOP over class-based OOP?

When I first started programming Javascript after primarily dealing with OOP in context of class-based languages, I was left confused as to why prototype-based OOP would ever be preferred to ...
34
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When writing object-oriented code, should I always be following a design pattern?

Is there a conceivable design pattern for any object-oriented program? I ask this because recently I saw an implementation of a Door class with a Lock. It was part of a test and the answer said that ...
34
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5answers
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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 ...
34
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8answers
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What is the real responsibility of a class?

I keep wondering if it is legitimate to use verbs that are based on nouns in OOP. I came across this brilliant article, though I still disagree with the point it makes. To explain the problem a bit ...
34
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6answers
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Why is “tight coupling between functions and data” bad?

I found this quote in "The Joy of Clojure" on p. 32, but someone said the same thing to me over dinner last week and I've heard it other places as well: [A] downside to object-oriented programming ...
34
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Programming SOLID Principles

Over time I could understand two parts of SOLID – the “S” and “O”. “O” – I learned Open Closed Principle with the help of Inheritance and Strategy Pattern. “S” – I learned Single Responsibility ...
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Does the ActiveRecord pattern follow/encourage the SOLID design principles?

I'm interested in whether ActiveRecord pattern, made famous from Ruby on Rails, encourages or discourages the use of SOLID design principles. For example, it seems to me that ActiveRecord objects ...
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3answers
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Why is an anemic domain model considered bad in C#/OOP, but very important in F#/FP?

In a blog post on F# for fun and profit, it says: In a functional design, it is very important to separate behavior from data. The data types are simple and "dumb". And then separately, you ...
33
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6answers
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LSP vs OCP / Liskov Substitution VS Open Close

I am trying to understand the SOLID principles of OOP and I've come to the conclusion that LSP and OCP have some similarities (if not to say more). the open/closed principle states "software ...
33
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17answers
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How can I feel more confident about my programming skills? [closed]

Programming isn't alien to me. I first starting doing markup (HTML, now please don't laugh at me) when I was 12 and a little bit of BASIC when I was 13 (I knew much about Flowcharts, Pseudocodes at ...
33
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1answer
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What's a generic word for both Methods and Attributes?

In a class diagram, each class contains methods and attributes. What's the correct word for describing both of them besides something generic such as contents or items? Context: The Orange class ...
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3answers
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Does Java development typically involve more subclassing than C#/.NET?

I've recently started looking at Android development. This has brought me back into the world of Java software development. The last time I worked with Java, I'll admit, I didn't understand OOP nearly ...
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7answers
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Why have private static methods?

I just wanted to clear up a question I have. What is the point of having a private static method as opposed to a normal method with private visibility? I would have thought an advantage to having a ...
32
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7answers
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Complete immutability and Object Oriented Programming

In most OOP languages, objects are generally mutable with a limited set of exceptions (like e.g. tuples and strings in python). In most functional languages, data is immutable. Both mutable and ...
32
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12answers
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Why does PHP have interfaces?

I noticed that as of PHP5, interfaces have been added to the language. However, since PHP is so loosely typed, it seems that most of the benefits of using interfaces is lost. Why is this included in ...
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18answers
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What would you do if your client required you not to use object-oriented programming?

I am writing a program to simulate the activity of ants in a grid (PDF). The ant can move around, pick up things and drop things. The problem is while the action of the ants and the positions of each ...
31
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9answers
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Are abstract classes / methods obsolete?

I used to create a lot of abstract classes / methods. Then I started using interfaces. Now I am not sure if interfaces aren't making abstract classes obsolete. You need a fully abstract class? ...
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4answers
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What exactly is procedural programming? How exactly is it different from OOP? Is it the same as functional programming?

I am programming in Java in a very object-oriented (OO) style. OOP comes very intuitively to me, but I have very little knowledge about other kinds of programming. What exactly is procedural ...
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2answers
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How to improve upon Bloch's Builder Pattern, to make it more appropriate for use in highly-extendable classes

I have been greatly influenced by Joshua Bloch's Effective Java book (2nd edition), probably more so than with any programming book I've read. In particular, his Builder Pattern (item 2) has had the ...
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6answers
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Is it okay to have code smells if it admits an easier solution to another problem? [closed]

A group of friends and I have been working on a project for the past little while, and we wanted to invent a nice OOP way of representing a scenario specific to our product. Basically, we're working ...
29
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9answers
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What is Object Oriented Programming ill-suited for? [closed]

In Martin Fowler's book Refactoring, Fowler speaks of how when developers learn something new, they don't consider when it's inappropriate for the job: Ten years ago it was like that with objects. ...
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5answers
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Pass ID or Object?

When providing a business logic method to get a domain entity, should the parameter accept an object or an ID? For example, should we do this: public Foo GetItem(int id) {} or this: public Foo ...
28
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8answers
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Is it acceptable to copy and paste long but straightforward code instead of wrapping them into a class or function?

Suppose I have a segment of code to connect to internet and show connection results like it: HttpRequest* httpRequest=new HttpRequest(); httpRequest->setUrl("(some domain .com)"); ...
28
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12answers
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Why should a class be anything other than “abstract” or “final/sealed”?

After 10+ years of java/c# programming, I find myself creating either: abstract classes: contract not meant to be instantiated as-is. final/sealed classes: implementation not meant to serve as base ...
28
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6answers
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Can you implement “object-oriented” programming without the class keyword?

Say we want to provide an abstraction of an "account" in a bank. Here's one approach, using a function object in Python: def account(): """Return a dispatch dictionary representing a bank ...
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Is splitting up a function into several inner functions an anti-pattern? [duplicate]

Imagine a long and complicated process, which is started by calling function foo(). There are several consecutive steps in this process, each of them depending on result of the previous step. The ...
28
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9answers
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Why should I declare a class as an abstract class?

I know the syntax, rules applied to abstract class and I want know usage of an abstract class Abstract class can not be instantiated directly but can be extended by other class What is the ...
28
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3answers
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Which is a better practice - helper methods as instance or static?

This question is subjective but I was just curious how most programmers approach this. The sample below is in pseudo-C# but this should apply to Java, C++, and other OOP languages as well. Anyway, ...
27
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11answers
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Did a gradual shift in methodology of writing code affect system performance? And Should I care?

Lest you be confused by what's to follow, here is the driving idea behind the question: I always intended the question to be what it is. I may not have articulated it well originally. But intent ...
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5answers
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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{ ...
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6answers
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What are the caveats of implementing fundamental types (like int) as classes?

When designing and implenting an object-oriented programming language, at some point one must make a choice about implementing fundamental types (like int, float, double or equivalents) as classes or ...
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Why most “well-known” imperative/OO languages allow unchecked access to types that can represent a 'nothing' value?

I have been reading about the (un)convenience of having null instead of (for example) Maybe. After reading this article, I am convinced that it would be much better to use Maybe (or something ...
26
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8answers
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Is it a good practice to use List of Enums?

I am currently working on a system where there are Users, and each user have one or multiple roles. Is it a good practice to use List of Enum values on User? I can't think of anything better, but this ...
26
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10answers
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How many are too many interfaces on a class? [closed]

I would probably consider it a code smell or even an anti-pattern to have a class that implements 23 interfaces. If it is indeed an anti-pattern, what would you call it? Or is it simply just not ...
26
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6answers
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Does learning a functional language make a better OOP programmer? [closed]

As a Java/C#/C++ programmer I hear a lot of talk about functional languages, but have never found a need to learn one. I've also heard that the higher level of thinking introduced in functional ...
26
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12answers
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How large is ok for a Class?

I’m a long time developer (I’m 49) but rather new to object oriented development. I’ve been reading about OO since Bertrand Meyer’s Eiffel, but have done really little OO programming. The point is ...
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10answers
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Given a herd of horses, how do I find the average horn length of all unicorns?

The question above is an abstract example of a common problem I encounter in legacy code, or more accurately, problems resulting from previous attempts at solving this problem. I can think of at ...
26
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9answers
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How to REALLY start thinking in terms of objects? [closed]

I work with a team of developers who all have several years of experience with languages such as C# and Java. Most of them are young enough to have been shown OOP as a standard way to develop ...
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10answers
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How would Functional Programming proponents answer this statement in Code Complete?

On page 839 of the second edition, Steve McConnell is discussing all the ways that programmers can "conquer complexity" in big programs. His tips culminate with this statement: "Object-oriented ...
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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 would it better to do that in the class itself? Or maybe mixing both? Which is recommended according to OOD ...
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Why is it bad to write something in language X as if you're writing a program in language Y in terms of using a shared coding paradigm [closed]

A while ago, I asked a question on SO about something written in C++, but instead of getting an answer to the problem at hand, the comments went all crazy on my coding style, even when I indicated ...
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9answers
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Is there any reason to use “plain old data” classes?

In legacy code I occasionally see classes that are nothing but wrappers for data. something like: class Bottle { int height; int diameter; Cap capType; getters/setters, maybe a ...
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Why are objects passed by reference?

A young co-worker who was studying OO has asked me why every object is passed by reference, which is the opposite of primitive types or structs. It is a common characteristic of languages such as Java ...