One of the four pillars of object-oriented programming (OOP), inheritance establishes a "is-a" relationship between objects. For example, a "Cat" object can be treated in code as any other "Animal" object because a "Cat" is-a "Animal".

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Object-oriented web scraping with Python

I usually write function-only Python programs, but have decided on an OOP approach (my first thereof) for my current program, a web-scraper. Here is the working code I wrote which I am looking to have ...
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63 views

Restricting types not related through inheritance without using instanceOf by creating own class hierarchy

Restricting types not related through inheritance without using instanceOf by creating own class hierarchy. It needs to interact with a key value data store, will ...
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117 views

Reusable REST service class for Angular2 in TypeScript

I am creating an Angular 2 web application using TypeScript. This application performs REST requests to a REST "service". For each REST resource in my service I create a separate "Service" class in ...
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62 views

Mortgage calculator in JavaScript

I'm learning JavaScript and decided to build this mortgage calculator as a starting point. For the most part it was reasonably straightforward, but when I implemented the graphs using D3 I found ...
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176 views

Follow up - Creating Inheritance hierarchy using function constructor

In continuation with this question, Animal class has four fields: name sound ...
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106 views

Creating Inheritance hierarchy using function constructor

Problem statement You need to create the Animal base class having four fields: a. name b. ...
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86 views

Logic Gate Simulator - Proper Encapsulation

So I was checking out the courses on InteractivePython, and I came across this example to demonstrate inheritance. My focus is on the Connector class and how it ...
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62 views

Adding new articles

Following is a working program to add new articles. The only thing I want is to check if there is any way to write it in a better way, or if the architecture is good as it is. Maybe I did not have to ...
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3answers
119 views

Polymorphically processing 2 & 3 dimensional objects

It seems there are a lot of "empty containers" (I do not know the correct, technical term) with regards to multiple levels of abstract classes and functional interfaces with little or no code. Is ...
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118 views

Creating n-dimensional mathematical vector classes through inheritance

Right now I have no knowledge of templates, but I just finished learning about inheritance, and wanted to apply it to a Vector3 class that I had already created. My ...
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1answer
93 views

Sorting polymorphic classes

I'm learning from "Jumping into C++" by Alex Allain (sample chapter and TOC) and solved the first problem in Chapter 26 "Inheritance and Polymorphism". I'm especially concerned about my use of ...
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4answers
188 views

An attempt at inheritance (Geometric Shapes)

I'm reading through the chapter on inheritance from C++ Primer 5th Edition. It asks Organize the following type into an inheritance hierarchy: (b) Geometric primitives (such as box, circle, ...
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46 views

Complicated inheritance [closed]

I found the below code in our code base at work, and I think it looks strange. The class RetainCounting is used for implementing reference counting. Should the IProvider really derive from ...
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37 views

Grids, Cells, and Inheritance

I want to build a grid and I have 2 concepts: Grid which is consist of Cell. Grid class is: ...
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482 views

Creature generator

Originally posted this here, and it was helpfully suggested to post in this forum. In the past couple of years I've returned part time to programming after a 15 year gap. I was C/UNIX. So, I've ...
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456 views

Java - Something similar to Abstract Factory?

I have many repositories stored in a map. User chooses some of them and then a downloading begins. Repository may be one of 4 types (see code below). ...
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2answers
157 views

Reuse a base class [Activity] handler in all sub classes for background work

We are using the Thread of a common base class but using its handler in all its sub classes. The code is working fine but is it the right way to go about? Our base class looks like this: ...
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1answer
91 views

The rounded box that wanted to be an arc

This is from Bjarne Stroustrup's C++ Programming: Principles and Practice, Chapter 13 Exercise 2: Draw a box with rounded corners. Define a class Box, ...
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3answers
179 views

Music collection with lyric songs and instrumental pieces

I have problems with dealing with derived classes that inherit from the same base class. I have 2 types of songs: Songs with lyrics that have: Title, Tags (sad, happy etc.), lyrics (one line), ...
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1answer
129 views

Multiple inheritance pattern for vehicle information

I wanted an easy way to augment objects, by adding functionality from any other object(s). More importantly, I needed a way to augment the object from multiple sources in a clean one-line solution. ...
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2answers
116 views

Base service for two different implementations

I have code that fetches different templates for HTML and CSS in the file system. The templates are stored in different folders, so I have two implementations for the code that fetches them, passing ...
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1answer
227 views

Optional base class template to get conditional data members

In generic code, I sometimes want to conditionally add a data member to a class template. Writing separate template specializations scales as 2^N for ...
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1answer
102 views

Lockable linked list

The existing design of class DList and DListNode is taken. The main criteria is to do successive updates in \$O(1)\$ time. Part ...
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1answer
247 views

Creating instances of all subclasses in Python

I have a superclass with several subclasses. Each subclass overrides the "solve" method with some a different algorithm for estimating the solution to a particular problem. I'd like to efficiently ...
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2answers
136 views

Infrastructure for my 2D game using Allegro

I am making a small 2D game with the use of Allegro 5 library. I am making use of inheritance e.g. sprite class as the base class and player class as the child class, but I want to know if it's a good ...
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1answer
139 views

Code Golf challenge that plays Mafia

I am working on writing a Code Golf King of the Hill challenge, the details of which can be read here. You can read the full code here. Briefly, the game proceeds in cycles of night then day. There ...
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71 views

Representing trajectory points using inheritance

Problem Background I need to represent trajectory points and trajectories (encapsulating these points) in the form of a collection of classes. All trajectory points have two essential elements: time ...
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Assigning functions for different location classes

Suppose in a School, you can only study, teach, or walk; in a Mall, you can only purchase, walk, or sell; ...
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3answers
52 views

Page Enum with overridden methods for the first and last members

I am managing the changing of views in an Android app using this enum and associated methods. I am particularly interested in the Page enum's use of overriding ...
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3answers
109 views

Is one-sided equality more helpful or more confusing than quick failure?

My question is about the equals() method. Most people implement equals() to start like: ...
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1answer
122 views

Using composition instead of inheritance

I have been using Entity Framework 6, AutoMapper, ASP.NET Web Api and hit a few problems along the way, each time it was recommended that I could change my code from Inheritance to use composition ...
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75 views

Generic classes with inheritance/equals/comparison operators

I would like to greatly reduce verbosity of following code fragment. What I'd like to do: Reduce number of occurrences of MaterialRangedParam<Value> and ...
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140 views

System for registering people

For a small administrative program, I have to be able to register people and their data. But, files are sometimes created through a phone call "on the fly" and then later certain data is added to the ...
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1answer
96 views

Generic Pickle-Aware Super-Class for Mixing Classes with and without __slots__ in Python

I want a generic super-class that I can easily subclass - and if desired add slots to my class - without having to worry about any pickle issues (with the lowest protocol). Is this in general a good ...
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0answers
122 views

MultiLevel JavaScript Inheritance

I'm making an experiment on JS, trying to build a framework for OOP. It's called Universe. The main purpose is to emulate a mini-universe, where classes are "created" with a defined behavior ...
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3answers
203 views

Implementing sequence abstraction

Below is the code that implements sequence abstraction using type abstraction Sequence (in Java): ...
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1answer
163 views

Calling common async code from a derived method

I'm implementing a number of classes in C# that have async methods. However, each of these methods needs to implement some boilerplate code that is common to all. Therefore I've implemented the common ...
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5answers
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Implement a Shape abstract class

To learn more about OOP, @nhgrif challenged me to implement a Shape abstract class (more details in code remarks below. Here is how I did it. Any and all advice appreciated! Shape.java ...
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Strategy Game Menus and OOP

Most of my experience is with Objective-C, so I am relatively new to Java inheritance. I understand that there are concepts such as abstract classes and interfaces, but I am still not totally sure ...
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702 views

Decomposing the animal kingdom

I have implemented a Mammal class hierarchy in Java. Is it an intelligent approach, with respect to decomposition, locality and procedural abstraction? ...
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1answer
944 views

A Singleton Base and derived class

I have a base and derived class since I need to have different kinds of concrete classes. I cannot use the getInstance() function in the base class since I cannot ...
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1answer
569 views

Creating users with different roles using .Net Identity 2.0 within Entity Framework

I am using .Net Identity 2.0 with Entity Framework 6.0. I have a Person class inheriting IdentityUser. I have a ...
2
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1answer
193 views

Dumping fields from Python objects

I am writing a small class that has one method: get_state. It is parameterless and returns a dictionary of all the names in self (look in its dict) that are not ...
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339 views

Video Store Rental Application

I'm in the middle of developing a video store rental application for a school project but am starting to question whether I'm going about things in the correct manner. Although the application is ...
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1answer
208 views

Generating a zoo of animals

The pattern I've come up here is for the AnimalGenerator itself, outside of the (abstract) Factory Pattern used within it. The factory classes themselves are not ...
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2answers
106 views

Inheriting methods of an immutable type

In my project, I have a type BalanceByBucket that is an immutable type and has a bunch of methods. I have another class called a ...
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1answer
49 views

Emulating class extending

I'm using the following piece of JavaScript to emulate class extending. Is this a valid way to go or does it have some drawbacks which should definitely be fixed? ...
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1answer
68 views

Seeking proper system for pairing types

My code below ensures that only land animals can be a "representatives" for Land while only ocean animals can be representatives for ...
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1answer
239 views

Displaying a list of players and their leagues

My question is mostly directed towards the principles of object-oriented programming. I have an Android application and one of the activities has a ListView. In ...
4
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1answer
86 views

Design/reiterate or code reuse for linked list

This is what my class hierarchy looks like. I have an abstract superclass, AbstractLinkedMyList, that contains common operations for both sorted and unsorted linked ...