I don't understand Access Modifiers in OOP. Why do we make for example in Java instance variables private and then use public getter and setter methods to access them? I mean what's the reasoning/logic behind this? You still get to the instance variable but why use setter and getter methods when you can just make your variables public? ...
I saw this example from php.net: <?php class MyClass { const MY_CONST = "yonder"; public function __construct() { $c = get_class( $this ); echo $c::MY_CONST; } } class ChildClass extends MyClass { const MY_CONST = "bar"; } $x = new ChildClass(); // prints 'bar' $y = new MyClass(); // prints ...
I am trying to get a Javascript object to use the "this" assignments of another objects' constructor, as well as assume all that objects' prototype functions. Here's an example of what I'm attempting to accomplish: /* The base - contains assignments to 'this', and prototype functions */ function ObjX(a,b) { this.$a = a, ...
Hi, I would like your guidance on how to create classes and their relationships (generalization, association, aggregation and composition) accurately from my USE case diagram (please see below). I am trying to create this class diagram so I can use it to create a simple online PHP application that allows the user to register an accoun...
I'm wondering if this kind of thing will ever be possible in PHP (and whether it already is and I'm just missing something...) <?php function test() { return array( 'id'=>10, 'name'=>'John' ); } echo 'Your name is: '.test()['name']; ?> I'd really like to be able to use returned arrays directly instead of first assigning them ...
I'm using my MOO project to teach myself Test Driven Design, and it's taking me interesting places. For example, I wrote a test that said an attribute on a particular object should always return an array, so -- t = Thing.new("test") p t.names #-> ["test"] t.names = nil p t.names #-> [] The code I have for this is okay, but it doesn...
Here I found this code: import java.awt.*; import javax.swing.*; public class FunWithPanels extends JFrame { public static void main(String[] args) { FunWithPanels frame = new FunWithPanels(); frame.doSomething(); } void doSomething() { Container c = getContentPane(); JPanel p1 = new JPan...
Hello everyone, It is mentioned in C++ FAQ site -- "larger derived class objects get sliced when passed by value as a base class object", what does slicing mean? Any sample to demonstrate? http://www.parashift.com/c++-faq-lite/value-vs-ref-semantics.html#faq-31.8 I am using VSTS 2008 + native C++ as my development environment. thanks...
I have question regarding composite pattern. Is the base class "Component" act like a pointer to point leaf object in "Composite" class? Edit: Let me ask my question in following words. "What is the relation between Composite and Component class?" Here is the uml class diagram of the pattern. ...
Hi, I wonder if anyone can help out here, I'm trying to understand how use an objects properties across multiple non class pages,but I can't seem to be able to get my head around everything i have tried so far. For example a class called person; class person { static $name; } but i have a number of different regular pages that...
class Node{ private: string name; Node** adjacent; int adjNum; public: Node(); Node(string, int adj_num); Node(const Node &); bool addAdjacent(const Node &); Node** getAdjacents(); string getName(); ...
Hi, The diagram below is my very first attempt at creating a UML class diagram describing a user login into a website. I'm sure its a poor design and full of flaws, but I'm hoping to learn from you guys how you would design a simple login like this. I'm particularly interested in your use of design patterns and which patterns you woul...
class Bouncy<T> extends Throwable { } // Error: the generic class Bouncy<T> may not subclass java.lang.Throwable Why doesn't Java support generic Throwables? I realize that type erasure complicates certain things, but obviously Java gets by with a lot already, so why not push it one more notch and allow generic Throwables, with c...
Hi, I am trying to figure out what 'topic' this is called, so I can learn more about it. Basically, I'm talking about designing my applications's architecture. I'm not talking about algorithms. More like -- this class should have these methods and these instance variables, and communicate with this class in this way, this class should...
In the inherited class I use the base constructor, but can't use class's members calling this base constructor. In this example I have a PicturedLabel that knows it's own color and has a image. A TypedLabel : PictureLabel knows it's type but uses the base color. The (base)image that uses TypedLabel should be colored with the (base)colo...
Let's assume that our system can perform actions, and that an action requires some parameters to do its work. I have defined the following base class for all actions (simplified for your reading pleasure): public abstract class BaseBusinessAction<TActionParameters> : where TActionParameters : IActionParameters { protected Base...
Im used to java and creating UML.. and i was wondering how can PHP be OOP, the objects live only until you make a request.. then they destroy, so if im using a database is useless to create a class and add the members (variables) to the class, they will be useless.. i cant pass the main system object from one page to another, or similar ...
I am new to java, I have seen in the code at many places where my seniors have declared as List myList = new ArrayList(); (option1) Instead of ArrayList myList = new ArrayList(); (option2) Can you please tell me why people use Option1, is there any advantages? If we use option2, do we miss out any advantages or features? ...
In the SRP, a 'responsibility' is usually described as 'a reason to change', so that each class (or object?) should have only one reason someone should have to go in there and change it. But if you take this to the extreme fine-grain you could say that an object adding two numbers together is a responsibility and a possible reason to ...
I am interested in understanding object-oriented programming in a more academic and abstract way than I currently do, and want to know if there are any object-oriented concepts Java and C++ fail to implement. I realise neither of the languages are "pure" OO, but I am interested in what (if anything) they lack, not what they have extra. ...