@Override annotation error (android prefs)
You can go to Project settings –> Java Compiler, and switch the compiler compliance level to 1.6. I have to do it every time i import an existing project.
overriding
‘Shadows’ vs. ‘Overrides’ in VB.NET
Overrides is the more normal qualifier. If the child class redefines a base class function in this way, then regardless of how a child object is referenced (using either a base class or a child class reference) it is the child function that is called. On the other hand, if the child class function Shadows … Read more
Can I get polymorphic behavior without using virtual functions?
You could down cast the base class pointer to the derived class and call the function. Base* obj = new Derived; Derived* d = static_cast<Derived*>( obj ); d->doSomething(); Since doSomething() is not declared virtual, you should get the derived implementation.
How to override the properties of a CSS class to avoid copying and renaming styles
There are different ways in which properties can be overridden. Assuming you have .left { background: blue } e.g. any of the following would override it: a.background-none { background: none; } body .background-none { background: none; } .background-none { background: none !important; } The first two “win” by selector specificity; the third one wins by … Read more
Delphi subclass visual component and use it
The closest equivilent to your XCode approach is to use an “interposer” class in Delphi. Basically, you do not change the code that the IDE creates for the standard TToolBar usage. You instead declare a new class that derives from the standard TToolBar component but is also named TToolBar and you make it visible to … Read more
Java: How to find if a method is overridden from base class? [duplicate]
This question helps demonstrate how to get the information of which class that method belongs to: How to quickly determine if a method is overridden in Java class.getMethod(“myMethod”).getDeclaringClass();
Overriding a method with different return types in java?
You can return a different type, as long as it’s compatible with the return type of the overridden method. Compatible means: it’s a subclass, sub-interface, or implementation of the class or interface returned by the overridden method. And that’s logical. If a method returns an Animal, and your derived class returns a Cow, you’re not … Read more
Why is there no parameter contra-variance for overriding?
On the pure issue of contra-variance Adding contra-variance to a language opens a whole lot of potential problems or unclean solutions and offers very little advantage as it can be easily simulated without language support: struct A {}; struct B : A {}; struct C { virtual void f( B& ); }; struct D : … Read more
Rails: Overriding ActiveRecord association method
You can use block with has_many to extend your association with methods. See comment “Use a block to extend your associations” here. Overriding existing methods also works, don’t know whether it is a good idea however. has_many :tags, :through => :taggings, :order => :name do def << (value) “overriden” #your code here super value end … Read more
Force child class to override parent’s methods
this could be your parent class: class Polygon(): def __init__(self): raise NotImplementedError def perimeter(self): raise NotImplementedError def area(self): raise NotImplementedError although the problem will be spotted at runtime only, when one of the instances of the child classes tries to call one of these methods. a different version is to use abc.abstractmethod. from abc import … Read more