overriding

Is it possible to override += in Python? John Kugelman Yes, override the __iadd__ method. Example: def __iadd__(self, other): self.number += other.number return self In addition to what's correctly given in answers above, it is worth explicitly clarifying that when __iadd__ is overriden, the x += y operation does NOT end with the end of __iadd__ method. Instead, it ends with x = x.__iadd__(y) . In other words, Python assigns the return value of your __iadd__ implementation to the object you're "adding to", AFTER the implementation completes. This means it is possible to mutate the left side of

I was looking at this blog post and had following questions: Why do we need the new keyword, is it just to specify that a base class method is being hidden. I mean, why do we need it? If we don't use the override keyword, aren't we hiding the base class method? Why is the default in C# to hide and not override? Why have the designers implemented it this way? Good questions. Let me re-state them. Why is it legal to hide a method with another method at all? Let me answer that question with an example. You have an interface from CLR v1: interface IEnumerable { IEnumerator GetEnumerator(); } Super

I am using PhoneGap 1.5.0, jQuery 1.7.1 and jQuery mobile 1.0.1 and trying to override the backbutton in Android as stated here or here . document.addEventListener("deviceready", onDeviceReady, false); // PhoneGap loaded function onDeviceReady() { console.log("PhoneGap Ready!"); // waiting for button document.addEventListener("backbutton", handleBackButton, false); } // handle the back button function handleBackButton() { console.log("Back Button Pressed!"); navigator.app.exitApp(); } But it only works on the first page of my app. After changing to a different page the backbutton does nothing

Say I have classes Foo and Bar set up like this: class Foo { public: int x; virtual void printStuff() { std::cout << x << std::endl; } }; class Bar : public Foo { public: int y; void printStuff() { // I would like to call Foo.printStuff() here... std::cout << y << std::endl; } }; As annotated in the code, I'd like to be able to call the base class's function that I'm overriding. In Java there's the super.funcname() syntax. Is this possible in C++? The C++ syntax is like this: class Bar : public Foo { // ... void printStuff() { Foo::printStuff(); // calls base class' function } }; Yes, class

Let's say I have three classes A, B and C. B extends A C extends B All have a public void foo() method defined. Now from C's foo() method I want to invoke A's foo() method (NOT its parent B's method but the super super class A's method). I tried super.super.foo(); , but it's invalid syntax. How can I achieve this? You can't even use reflection. Something like Class superSuperClass = this.getClass().getSuperclass().getSuperclass(); superSuperClass.getMethod("foo").invoke(this); would lead to an InvocationTargetException , because even if you call the foo-Method on the superSuperClass, it will

Say I have a base class TestBase where I define a virtual method TestMe() class TestBase { public virtual bool TestMe() { } } Now I inherit this class: class Test1 : TestBase { public override bool TestMe() {} } Now, using Reflection, I need to find if the method TestMe has been overriden in child class - is it possible? What I need it for - I am writing a designer visualizer for type "object" to show the whole hierarchy of inheritance and also show which virtual methods were overridden at which level. Given the type Test1 , you can determine whether it has its own implementation declaration