There is no polymorphism for fields in Java. There is however, inheritance. What you’ve effectively done is create two fields in your Rectangle class, with the same name. The names of the field are, effectively: public class Rectangle { public int Shape.x; public int Rectangle.x; } The above doesn’t represent valid Java, its just an … Read more
You are not modifying the open method inherited by XMLHttpRequest objects but just adding a method to the XMLHttpRequest constructor which is actually never used. I tried this code in facebook and I was able to catch the requests: (function() { var proxied = window.XMLHttpRequest.prototype.open; window.XMLHttpRequest.prototype.open = function() { console.log( arguments ); return proxied.apply(this, [].slice.call(arguments)); … Read more
Why are we forced to call super.method()? The classes that make up the Android SDK can be incredibly complex. For instance, both activities and fragments must perform a number of operations in order to function properly (i.e. managing life cycle, optimizing memory usage, drawing the layout to the screen, etc.). Requiring the client to make … Read more
You can simply use: mvn –settings YourOwnSettings.xml clean install or mvn -s YourOwnSettings.xml clean install
=========================================================================== Update: July 19, 2017 Now the Rails documentation is also suggesting to use super like this: class Model < ActiveRecord::Base def attribute_name=(value) # custom actions ### super(value) end end =========================================================================== Original Answer If you want to override the setter methods for columns of a table while accessing through models, this is the way to … Read more
It’s an annotation that you can use to tell the compiler and your IDE that you intend the method that has that annotation to be an override of a super class method. They have warning/errors in case you make mistakes, for example if you intend to override a method but misspell it, if the annotation … Read more
Edit: It’s now six years since the original answer was written and a lot has changed! If you’re using a newer version of JavaScript, possibly compiled with a tool like Babel, you can use real classes. If you’re using the class-like component constructors provided by Angular or React, you’ll want to look in the docs … Read more
The term used to describe this is “hiding”, rather than “overriding”. A member of a derived class will, by default, make any members of base classes with the same name inaccessible, whether or not they have the same signature. If you want to access the base class members, you can pull them into the derived … Read more
The signature of fooMethod(Class<?>) is the same as the signature of fooMethod(Class) after erasure, since the erasure of Class<?> is simply Class (JLS 4.6). Hence, fooMethod(Class) is a subsignature of the fooMethod(Class<?>) but not the opposite (JLS 8.4.2). For overriding with instance methods you need the overriding method to be a subsignature of the overridden … Read more
Use a virtual method to get a reference to the static variable. class Base { private: static A *a; public: A* GetA() { return a; } }; class Derived: public Base { private: static B *b; public: A* GetA() { return b; } }; Notice that B derives from A here. Then: void Derived::paint() { … Read more