How to make a class protected for inheritance?
I would like to do the same thing I do in Java with the final keyword. I tryed to use const keyword... but it doesn't work. How can I prevent other class to inherit from my class? ...
oop
Poll: Correct behavior of equality when passed object does not match LHS type?
I asked a related question about findbugs, but let's ask a more general question. Suppose that I am working with an object-oriented language in which polymorphism is possible. Suppose that the language supports static type checking (e.g., Java, C++) Suppose that the language does not allow variance in parameters (e.g., Java, again...)...
Is Multiple Inheritance Evil?
Why is multiple inheritance considered to be evil while implementing multiple interfaces is not? Especially when once considers that interfaces are simply pure abstract classes? (More or less) duplicate of What is the exact problem with multiple inheritance?, Multiple Inheritance in C#, and some others... ...
Help with design
I think I am pretty good with programming C# syntax. What I am looking for now is some resources, books(preferable), websites, blogs, that deal with the best way to design object oriented Desktop Applications and Web applications, especially when it comes to data and databases. Thanks ...
Why can't Delphi variants hold objects?
Why can't Delphi variants hold objects? More importantly, what's the reason behind this limitation? ...
Should a long method used only once be in its own class or in a function?
A lot of times in code on the internet or code from my co-workers I see them creating an Object with just one method which only gets used once in the whole application. Like this: class iOnlyHaveOneMethod{ public function theOneMethod(){ //loads and loads of code, say 100's of lines // but it only gets used once in the who...
How often do you need to create a real class hierarchy in your day to day programming?
I create business applications with heavy database use. Most of the programming work is just to connect components to the database and modifying components to adapt to general interface behaviour. I mostly use Delphi with its rich VCL library, and generally buy components needed. I keep most of the business logic in the database. I rarel...
Objectively Good OO Design Principles
Premise I believe that there is a way to objectively define "Good" and "Bad" Object-Oriented design techniques and that, as a community we can determine what these are. This is an academic exercise. If done with seriousness and resolve, I believe it can be of great benefit to the community as a whole. The community will benefit by hav...
When is it prudent to use friendship in OOP?
I'm currently getting through the http://www.cplusplus.com tutorial and I came across this section here: http://www.cplusplus.com/doc/tutorial/inheritance.html that deals with the subject of friend functions and friend classes in C++. My question is, when When is it prudent to use friendship when creating a program? The only clue I g...
What is the difference between Abstraction and Polymorphism
I seem to not understand two OOP concepts very well. Could you explain what abstraction and polymorphism are, preferably with real examples and code? Thank you. ...
late static binding: which languages commonly used for web development support it?
Lately I've been seeing a lot of talk regarding PHP's lack of late static binding until 5.3. From what I've read proper implementations of stuff like ActiveRecord are not possible until the language has this feature. So, I'm curious about: Which languages do support it, specifically those commonly associated with web development suc...
What is the difference between holding object of a class and agregating them?
May be the questions sounds newbie, but I can not distinguish the difference between agregating and holding. What does it mean in terms of, let`s say, C++? I suppose when the object of class A holds (or instantiates) objects of class B, it uses it to perform some functions by itself. For example: class A { int state; public: A(int s...
DB Design: more tables vs less tables
Say I want to design a database for a community site with blogs, photos, forums etc., one way to do this is to single out the concept of a "post", as a blog entry, a blog comment, a photo, a photo comment, a forum post all can be thought as a post. So, I could potentially have one table named Post [PostID, PostType, Title, Body .... ], ...
Why should you not use Number as a constructor?
I entered this statement in JSLint: var number = new Number(3); And received the following message: Do not use Number as a constructor. Why is that? The statement is creating a number object, not a primitive value, so I don't see why using new is a problem. EDIT: Thanks for all the responses. They've got me thinking further, so...
Book opinion - The Object Oriented Thought Process, 3rd Edition
http://www.amazon.com/Object-Oriented-Thought-Process-Developers-Library/dp/0672330164 Is this book worth reading for a developer who is familiar with OO Programming in C++ and PHP5, but dosen't really get OO? (me) Please also suggest the alternatives you think are better and targeted to similar audience. The book doesn't have be in any...
Question about object.method in JavaScript
This is a follow-up question to this one. Take a look at these two examples: var number1 = new Number(3.123); number1 = number1.toFixed(2); alert(number1); var number2 = 3.123; number2 = number2.toFixed(2); alert(number2); I realize they both end up with the same value, but is it correct thinking to refer to a method of a primitiv...
Best way to compare objects by multiple fields?
Assume you have some objects which have several fields they can be compared by: public class Person { private String firstName; private String lastName; private String age; /* Constructors */ /* Methods */ } So in this example, when you ask if: a.compareTo(b) > 0 you might be asking if a's last name comes be...
Accessing the Document class in AS3
How can instantiated classes access the Document class? Even after I name the Document class using the Properties bar in Flash, attempting to access it from other classes usually fails, saying "attempting to access an undefined property... One solution is always casting the Document class to itself! eg. Main(Main).globalMethod(); Bu...
Container Interface - Detailed Explanation
I was just reading up a lecture which breifly went over Container Interface. I didn't fully comprehend the material and couldn't find too much via google. What I was wondering was, can any of you explain it in real world terms. Also explaining alternatives and when its better to use which? If that is the case. Thanks for any help ...
Why IsNan is a static method on the Double class instead of an instance property ?
The question is in the title, why : return double.IsNaN(0.6d) && double.IsNaN(x); Instead of return (0.6d).IsNaN && x.IsNaN; I ask because when implementing custom structs that have a special value with the same meaning as NaN I tend to prefer the second. Additionally the performance of the property is normally better as it avoid ...