abstract

I'd like to create an abstract class in c#, that "inherits" from different interfaces, but leaves the concrete implementation to the subclass. The compiler however complains, that the class doesnt implement the methods specified in the interfaces. I'm used to Java where this always worked, so I'm not sure how it is supposed to work in c#. Anyway, this is my code: public abstract class MyClass : IDisposable, IPartImportsSatisfiedNotification { private string name; public MyClass(string name) { this.name = name; } } Add abstract methods: public interface IPartImportsSatisfiedNotification { void

I have the task to write own containers Linked_list and Array_list . I have one interface for them: typedef int value_type; class Container { public: class Iterator { public: Iterator(); Iterator(value_type* other); Iterator(const Iterator& other); Iterator& operator=(const Iterator& other); ... }; Container(); Container(const Container& other); ~Container(); virtual value_type& front() const=0; virtual value_type& back() const=0; virtual Iterator begin() const=0; // ... }; I did derived classes Linked_list and Array_list: class Linked_list:public Container { public: long int cur_size; List

I am using a component suite which has many abstract classes. Now I want to apply polymorphism but I am getting Error Abstract Class when I create my object. Should I override all methods which are virtual even if I don't need it? Are there any workaround or solution? In order to make an instance of a class, you need to override all methods that are declared as virtual abstract. Even if you don't use them. If you really want a work around, you can use empty methods. But I won't recommend that. And to add some more information on the subject: A method is abstract if it is declared with virtual

I am wondering what the semantics of using the abstract keyword in combination with a trait is. If the trait does not define any abstract methods, the abstract keyword does not prevent me from creating an instance: scala> abstract trait T defined trait T scala> new T{} res0: java.lang.Object with T = $anon$1@12cd927d On the other hand, if the trait does define an abstract method, I cannot create an instance (without implementing this method of course) no matter if the abstract keyword is present or not: scala> abstract trait T { def foo : Unit } defined trait T scala> new T{} <console>:9:

Why is it allowed to change the visibility and existence of getters or setters in a property when implementing an interface? interface IFoo { string Bar { get; } } class RealFoo : IFoo { public RealFoo(string bar) { this.Bar = bar; } public string Bar { get; private set; } } class StubFoo : IFoo { public string Bar { get; set; } } ...and not legal to do the same when implementing an abstract class? abstract class AbstractFoo : IFoo { public abstract string Bar { get; } } class RealFoo : AbstractFoo { public RealFoo(string bar) { this.Bar = bar; } // Cannot override because 'Bar' does not have

this is the code: import java.awt.*; import java.applet.*; public class anim1 extends Applet{ public void paint (Graphics g) { g.drawString("",400,300); } public static void main(String ad[]) { anim1 a=new anim1(); Graphics g1; a.paint(g1); } } It says that g1 is not initialized. But how do I initialize an abstract class? Well there are two issues here 1: Graphics g1; a.paint(g1); And you are getting the error that G1 is not initialized. That's because the variable g1 is never set to anything, and that causes a compile error. To get the code to compile, you would need to, at the very least do