I have ClassA and ClassB, with ClassA being the superclass. ClassA uses NodeA, ClassB uses NodeB. First problem: method parameters. ClassB needs NodeB types, but I can't cast from the subclass to the superclass. That means I can't set properties which are unique to NodeB's. Second problem: When I need to add nodes toClassB, I have to ...
I want to build a simple app (probably in MS Access) for a simple small-business database. We have fairly typical entities -- customer, contact, worker, supplier, sub-contractor. These are all variations of some hypothetical parent class, e.g. person. Is it worth it to try to reflect this hierarchy in the tables and forms used by such...
I have several classes that extend C and I would need a method that accepts any argument of type C. But in this method I would like to know if I'm dealing with A or B. * public A extends C public B extends C public void goForIt(C c)() If I cast how can I retrieve the type in a clean way (I just read using getClass or instanceof is o...
I've just made myself up a problem and am now wondering how to solve it. To begin with, I'm using some third-party components, including some calendar controls like schedule and timeline. They're used in the project classes more or less like that: Friend Class TimeBasedDataView 'some members End Class Friend Class ScheduleDataView...
Is Object the base class of all objects in Javascript, just like other language such as Java & C#? I tried below code in Firefox with Firebug installed. var t = new Object(); var s1 = new String('str'); var s2 = 'str'; console.log(typeof t); console.log(typeof s1); console.log(typeof s2); The console output is object object string ...
@interface ClassB <ClassADelegate> : ClassA id <ClassBDelegate> delegate; @end As the code says, ClassB subclasses from ClassA and handles the formation protocol of Class A. However, the variable "delegate" will be duplicated. (ClassA also has "delegate") In fact, it can be done without subclassing, but it seems the code is cumberso...
I have a problem trying to map an inheritance tree. A simplified version of my model is like this: @MappedSuperclass @Embeddable public class BaseEmbedded implements Serializable { @Column(name="BE_FIELD") private String beField; // Getters and setters follow } @MappedSuperclass @Embeddable public class DerivedEmbedded exten...
I have code that looks like this: public class A { public void doStuff() { System.out.print("Stuff successfully done"); } } public class B extends A { public void doStuff() { System.out.print("Stuff successfully done, but in a different way"); } public void doMoreStuff() { Syste...
I'm working on a huge, old project with a lot of brittle code, some of which has been around since the .NET 1.0 era, and it has been and will be worked on by other people... so I'd like to change as little as possible. I have one project in my solution that contains DataSet.xsd. This project compiles to a separate assembly (Data.dll). ...
I am just starting to use the Entity Framework 4 for the first time ever. So far I am liking it but I am a bit confused on how to correctly do inheritance. I am doing a model-first approach, and I have my Person entity with two subtype entities, Employee and Client. EF is correctly using the table per type approach, however I can't ...
Lets say I have a parent class class parent { } ..... This parent has three sub class class child1 { } class child2 { } class child3 { } and these child classes have further smaller parts like class child1subpar1 { } class child1subpar2 { public function foo() { echo "hi"; } } class child2subpar1 { }...
Maybe I just don't know what to search for, but I'm going a little bonkers here trying to figure out how to create a collection of inherited classes. The base class, I will never use. Basically, I have 3 components: A base class call ImageFormat Child classes of ImageForm Code in Sub Main() to loop create a collection and loop through...
Why is it that in Java, a superclass' protected members are inaccessible by an indirect subclass in a different package? I know that a direct subclass in a different package can access the superclass' protected members. I thought any subclass can access its inherited protected members. EDIT Sorry novice mistake, subclasses can access a...
Hi All, I was going through C# Brainteasers (http://www.yoda.arachsys.com/csharp/teasers.html) and came across one question: what should be the output of this code? class Base { public virtual void Foo(int x) { Console.WriteLine ("Base.Foo(int)"); } } class Derived : Base { public override void Foo(int x) { ...
So I've got a form... The relevant CSS is (I think): .libform input { background-color:transparent; color:#000; border-left:0; border-right:0; border-top:0; border-bottom: 1px solid #555; margin: 0 5px 1px 5px; display:inline-block; } .libform input:focus { border:0; border-bottom: 1px dotted #000; color:#939; background-color:#fed; } ....
This question is built on top of many assumptions. If one assumption is wrong, then the whole thing falls over. I'm still relatively new to Python and have just entered the curious/exploratory phase. It is my understanding that Python does not support the creating of classes that cannot be subclassed (final classes). However, it seems t...
Hi, In my program I have the following class hierarchy: class Base // Base is an abstract class { }; class A : public Base { }; class B : public Base { }; I would like to do the following: foo(const Base& one, const Base& two) { if (one == two) { // Do something } else { // Do something else } } I have issues ...
When you want to inherit from a class in C++, is it illegal to have std declared in the first line below? #ifndef HWEXCEPTION_H #define HWEXCEPTION_H #include <stdexcept> class HWException : public std::run_time_error { void testException(int num); }; #endif vs using std::run_time_error class MyClass : public run_time_error ...
Hello, All! Is somebody have an experience using inheritance in PostgreSQL? Is it worth to use it, or better to keep hands of :)? In which situation you would use it? To be true I'm a little bit in doubt about mixing relational and OO models... ...
I have the following code #include <iostream> #include <vector> class Entity { public: virtual void func() = 0; }; class Monster : public Entity { public: void func(); }; void Monster::func() { std::cout << "I AM A MONSTER" << std::endl; } class Buddha : public Entity { public: void func(); }; void Buddha::func() { std...