oop

问题 What i want is the ability to make "final traits" with the behaviour as described below. I realise this is not possible with traits(or is it? that would make me so happy), but I'm just trying to convey what I want to do. So, i want to have a trait that is trait Content { public final function getPostContent(){ /*...*/ } public final function setPostContent($content){ /*...*/ } } What I want is Marking the functions in the traits as final making sure that if a class uses this trait, the trait

问题 What i want is the ability to make "final traits" with the behaviour as described below. I realise this is not possible with traits(or is it? that would make me so happy), but I'm just trying to convey what I want to do. So, i want to have a trait that is trait Content { public final function getPostContent(){ /*...*/ } public final function setPostContent($content){ /*...*/ } } What I want is Marking the functions in the traits as final making sure that if a class uses this trait, the trait

问题 From Wikipedia, Liskov's notion of a behavioral subtype defines a notion of substitutability for objects; that is, if S is a subtype of T, then objects of type T in a program may be replaced with objects of type S without altering any of the desirable properties of that program (e.g. correctness). Suppose the following class hierarchy: The base abstract class - AnimalWithFur . It has a read-only property furColor that is overridden in successors. Base class's successor - Cat , which overrides

问题 I am writing a GUI in Tkinter using Python 2.11 using an OOP approach and trying to learn inheritance. I wrote a child class called ButtonField which is inherited from tk.Button. Inside ButtonField I have a method called pressMe which changes the color and text of the button when pressed. My eventual goal is to have more buttons in the GUI and all the associated methods contained in the ButtonField class for cleaner and more manageable code. When I press the Button the text "In Press Me

问题 I'm developing a service oriented platform for retrieving, creating and updating entities from DB. The point here is that every single java entity extends AbstractEntity , so for example, I have, MyCar extends AbstractEntity implements Serializable This AbstractEntity has common fields (such as id or audit ones). So I have already developed a GenericReadService that, receiving a classname and a parameterMap , can read any entity and creates a EntityActionResult<T> including a List<T extends

问题 in the php documentation it says: The Scope Resolution Operator (also called Paamayim Nekudotayim) or in simpler terms, the double colon, is a token that allows access to static, constant, and overridden properties or methods of a class. i get an error when i try to access overridden (not static) parent properties: class foo { public $bar = 'foobar'; } class baz extends foo { public $bar = 'bazbar'; public function get_bar() { echo parent::$bar; //Fatal error: Access to undeclared static

问题 I want to create an array of polymorphic objects which have constructors taking different dummy arguments depending on their dynamic type. Having read about user-defined and structure constructors, I see no way to apply these concepts to dynamically allocated objects. Having a background in C++, I was used to the notion that I could use one and the same constructor "member function" when allocating objects either dynamically or on the stack, but how can I explicitly call user-defined Fortran

问题 Take this simple code: class MyClass { public $customFunction = array(); public function run($name){ call_user_func($this->customFunction[$name]); } } //> Usage: $c = new MyClass(); $c->customFunction['first'] = function (){ /* some code*/ }; $c->run('first'); This cose works as excpted. I add that function to $customFunction and then i can call it form run(); method. The problem comes when in my injected function I try to do something object-related, for example if i add this function: $c-

问题 Take this simple code: class MyClass { public $customFunction = array(); public function run($name){ call_user_func($this->customFunction[$name]); } } //> Usage: $c = new MyClass(); $c->customFunction['first'] = function (){ /* some code*/ }; $c->run('first'); This cose works as excpted. I add that function to $customFunction and then i can call it form run(); method. The problem comes when in my injected function I try to do something object-related, for example if i add this function: $c-

问题 I'm having trouble designing some classes. I want my user to be able to use the Character() class by passing in an argument for the type of character (e.g. fighter/wizard). Dummy code: class CharClass(): def __init__(self, level): self.level = level class Fighter(CharClass): # fighter stuff pass class Wizard(CharClass): # wizard stuff pass class Character(): #? def __init__(self, char_class): # should inherit from Fighter/Wizard depending on the char_class arg pass For example, after calling: