Inheritance is a way to reuse code of existing objects, or to establish a subtype from an existing object, or both, depending upon programming language support.

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Is this the solution to static inheritance?

I've seen a lot of posts recently on why Singletons should be avoided. However, I can't see any of those problems with the following solution to a common problem: static inheritance. For example, I ...
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4answers
1k views

Why 'List<E>' is an 'interface' but not 'abstract class'?

Amidst defining the hierarchy, firstly, one can think to embed the abstract method(behavior) in abstract class only because the derive concrete class possess that behavior as core behavior with it's ...
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2answers
44 views

Expressing interface inheritance in natural language [duplicate]

In object-oriented programming, when you extend a class you establish an is-a relationship between a new subtype and its parent(s), i.e. B is an A (aka code inheritance). When you compose a class with ...
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1answer
611 views

Changing method signature for implementing classes in PHP

Is there any decent work around to PHP's lack of Generics that allow static code inspection to detect type consistency? I have an abstract class, that I want to sub-class and also enforce that one of ...
5
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2answers
482 views

Is it possible to refactor inheritance to composition when virtual methods are called inside the base class?

Let's say I have a class called Country and two subclasses called AI and Player. The Country class has a number of virtual methods to allow player-specific or AI-specific behavior. I want to make it ...
3
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2answers
294 views

How do I override the Type of members in a base class from the derived class?

I have two classes that know each other in a many-to-many relationship. Now I want to have two additional classes that inherit from the existing classes. The association between the inherited classes ...
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1answer
58 views

How Do I Create A Module* For A Class That Relies On Another Module?

*I'm using "Module" to mean some extension of a class, either through inheritance or composition. Say I have one of the following declarations of an Entity: using EUnit = int; class Entity : /*With ...
2
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5answers
131 views

Should I use inheritance to differentiate objects even if they have the same fields?

Consider this simple class that models a real world mobile device: /// <summary> /// Model that represents a device. /// </summary> public class Device { public DateTime ...
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10answers
4k views

Is it okay to have objects that cast themselves, even if it pollutes the API of their subclasses?

I have a base class, Base. It has two subclasses, Sub1 and Sub2. Each subclass has some additional methods. For example, Sub1 has Sandwich makeASandwich(Ingredients... ingredients), and Sub2 has ...
0
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2answers
285 views

block access to area/controller's methods but allow inherited controller to run methods, asp .net mvc5

I am trying to find out how to block a whole area/controller from being accessed by typing url website.com/area1/basecontroller/method1 (this area also contains the views that will be displayed) , ...
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14answers
6k views

How can I explain the usefulness of Inheritance? [closed]

When trying to explain the concept of Inheritance in OOP, the common example is often the mammals example. IMHO, this is really a bad example, because it will lead the newbies to use this concept the ...
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0answers
47 views

Class Interfaces with Multiple Classes and Dependency Injection

NOTE ON QUESTION TITLE: I did not really even know how to phrase the title so if someone can edit and make it more articulate I would really appreciate it. QUESTION: Basically, what I'm trying to do ...
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1answer
48 views

Keeping lists of Objects, some with, some without inheritance

Let's say I have two classes, Foo and ExtendedFoo where ExtendedFoo inherits from Foo. Foo has a method .getValue() which returns a number, ExtendedFoo also has .increaseValue() which adds to the ...
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2answers
506 views

Object inheritance and method parameters/return types - Please check my logic

I'm preparing for a test and doing practice questions, this one in particular I am unsure I did correctly: We are given a very simple UML diagram to demonstrate inheritance: I hope this is clear, it ...
0
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3answers
188 views

Why does an interface extend an interface instead of implementing it?

In Java suppose that I have interface A: public interface A { // foo } I also have interface B: public interface B extends A { // foo + bar } Why does interface B extend interface A ...
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2answers
159 views

Why is it bad to have one mechanism for inheritance and subtyping?

It is quite well-known that (class) inheritance and subtyping (sometimes called interface inheritance) are different things: inheritance is a mechanism for sharing code, while subtyping is a ...
8
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2answers
734 views

Are there any OO languages without inheritance?

During a code review today, a colleague of mine said something interesting: prototype is only useful when you need inheritance - and when's inheritance ever a good idea? I thought about this and ...
4
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1answer
41 views

Modular Database, Inheritance of Schema

Consider multiple relational database schemas that have an inheritance dependency structure as known from OOP systems: Tables are just a placeholder for arbitrary database objects such as Views, ...
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1answer
187 views

Inheritance or Composition?

Let's say I have a main class A and another class B. In the B class the user can change some settings and variables of the program that belongs to A, I want to be able to apply these changes to the A ...
2
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5answers
729 views

Is there an alternative to instanceof when filtering a Java stream by class?

I have an unexpected situation in a project in which all types extending one class are packed into a Java collection; but only a specific extension of that class contains an additional method. Let's ...
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4answers
209 views

Fixing class Hierarchy design mistakes due to incorrect inheritance

I have a code like this. My derived class man, may not properly have a member function declared pure virtual higher up the hierarchy. eg. WagTail here class mammal{ public: virtual void WagTail() ...
0
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1answer
168 views

Should I always call super in Java? [duplicate]

Anti-pattern considerations aside, should I always call super in Java when overriding methods, even when the method is empty? Take a look at the code below, this is an excerpt from AsyncTask and can ...
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1answer
113 views

How to handle custom logic for multiple customers

We got a project where we have to process certain requests which the customer sends. The request is either in a generic format or in a customer format (all xml) which is then converted to the generic ...
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5answers
202 views

classes/inheritance, how do I handle special cases that require more change

I often find myself in this situation where I have a base class that does a lot of graphics. There are, for example, three strings that are positioned top, middle, bottom of an element. Like a scale ...
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2answers
112 views

Should I extend an interface or keep it independent?

I'm trying to decide whether to extend a base interface with additional methods or create several independent interfaces. I have a Task interface that looks like this interface Task { public ...
36
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11answers
4k views

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 ...
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4answers
5k views

Java class to enforce an implementation of super classes' public methods

I have the following : public Class A { public void methodA() { .... } public void methodB() { .... } } I don't have control over Class A. I would like to create ...
3
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1answer
157 views

How to design similar purpose static methods

I know that you cannot override static functions, but for what I'm looking to do, it seems like the logical way to design my class. I have a method that is associated with my abstract class, that i ...
4
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1answer
402 views

Traits, Inheritance and Interfaces in Groovy, when to use them?

I'm learning groovy and I've just learned about the new feature added in 2.3, which is the addition of Traits. Now to me it seems like Traits allow you to do basically everything a super-class and an ...
0
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1answer
57 views

Implementing an interface already implemented by a parent class?

If a class extends a parent which defines an interface, should that class also explicitly implement the interface? As an example, is it better to include or remove the portion in square brackets ...
0
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1answer
68 views

refactor by inheritance or composition for large class that depend on common state [duplicate]

I have a huge class (>1000 lines), in which all methods depend on a small set of attributes in that class. I can think of 2 quick ways of refactoring. I keep it as a huge object, but split related ...
0
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3answers
82 views

Heuristics on when should one subclass and when not [closed]

Are there any good tips, when one should subclass and when should not? It's clear that we should not subclass when we want to reuse a single method of some class we override all methods, changing ...
2
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3answers
287 views

Is it appropriate to use inheritance to prevent code duplication of the logic for a user control?

Suppose I have two or more UserControl implementations with vastly different implementations but near identical code-behind. One strategy to avoid code duplication is as follows: Change each ...
0
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1answer
103 views

Class Table Inheritance: do child tables need a primary key?

I'm using the Class Table Inheritance architecture with my application and have read Fowler. When mapping my database tables to classes in code, I've realized I have no need for an "ID" property on ...
81
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9answers
8k views

Is there any “real” reason multiple inheritance is hated?

I've always liked the idea of having multiple inheritance supported in a language. Most often though it's intentionally forgone, and the supposed "replacement" is interfaces. Interfaces simply do ...
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3answers
174 views

Does overriding a method affect a superclass's call?

I'm trying to understand some of the nuances of inheritance but I can't find an answer to this question. Consider the following: class SuperClass { method foo { print "in SuperClass.foo" ...
0
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2answers
156 views

Inheritance is a null property in the parent a bad practice?

I am not a very experienced programmer. So I ask. The field in question is the "Amount" field. I store an amount only in a couple levels of the derived class. The code is a slice of the POCO ...
15
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8answers
3k views

Is it good practice to inherit from generic types?

Is it better to use List<string> in type annotations or StringList where StringList class StringList : List<String> { /* no further code!*/ } I ran into several of these in Irony.
2
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1answer
359 views

The Better Parts and Delegation: Is Crockford Too Extreme?

Douglas Crockford has recently been giving a talk called The Better Parts. The gist of the talk is that JavaScript developers should actually avoid a superset of the The Bad Parts, which now includes ...
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1answer
57 views

Compose nested EventEmitters elegantly

I am developing a server-side JavaScript tool, and trying to do so in a modular way. I have a Parser class that is an EventEmitter - you call parse and it will eventually emit data and end events. It ...
1
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0answers
73 views

How does one enforce the implementation of a static method? [duplicate]

Of course the answer to the question above is, "you can't". But I didn't have a better way of describing what I'm looking for. If I did, I wouldn't be asking this question. My problem stems from a C# ...
2
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1answer
149 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 ...
3
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2answers
94 views

Database design for polymorphic data

I have an application that needs to log communications with users over several different mediums: Email, SMS, Voice, Website Announcements, etc.. in a traditional database. I have considered 3 ...
2
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6answers
749 views

Confusion about inheritance

I know I might get downvoted for this, but I'm really curious. I was taught that inheritance is a very powerful polymorphism tool, but I can't seem to use it well in real cases. So far, I can only ...
2
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2answers
185 views

Is doing Parent.call from the child object a right way to implement Inheritance in JavaScript?

I came across this piece of code it didnt look that right to me. Is it the right way to implement SUPER in javascript. if not what is the right way? function Person(name){ this.name = name; } ...
13
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6answers
24k views

Why are constructors not inherited?

I am confused as to what the problems could be if a constructor was inherited from a base class. Cpp Primer Plus says, Constructors are different from other class methods in that they create ...
-1
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2answers
88 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 ...
2
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3answers
306 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 ...
2
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4answers
224 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 ...
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1answer
362 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 ...