overriding

What is “override-equivalence” and how is it related to @Override?

由 一笑奈何 提交于 2019-12-10 00:52:21
问题 Reading the Javadoc for the @Override annotation, I came across the following rule: If a method is annotated with this annotation type compilers are required to generate an error message unless at least one of the following conditions hold: The method does override or implement a method declared in a supertype. The method has a signature that is override-equivalent to that of any public method declared in Object. I'm clear on the first point, but I'm unsure about the second one. What does it

Why is overriding of static methods left out of most OOP languages?

由 ▼魔方 西西 提交于 2019-12-10 00:30:56
问题 It is certainly not for good OOP design - as the need for common behavior of all instances of a derived class is quite valid conceptually. Moreover, it would make for so much cleaner code if one could just say Data.parse(file) , have the common parse() code in the base class and let overriding do its magic than having to implement mostly similar code in all data subtypes and be careful to call DataSybtype.parse(file) - ugly ugly ugly So there must be a reason - like Performance ? As a bonus -

Scala automatic getter and setter overwriting with custom _=

由 风格不统一 提交于 2019-12-09 18:22:39
问题 In scala there is no difference for the user of a class between calling a method or accessing some field/member directly using val x = myclass.myproperty. To be able to control e.g. setting or getting a field, scala let us override the _= method. But is = really a method? I am confused. Let's take the following code: class Car(var miles: Int) var myCar = new Car(10) println(myCar.miles) //prints 10 myCar.miles = 50 println(myCar.miles) //prints 50 Same goes for this code (notice the double

Calling child class method from parent

由 亡梦爱人 提交于 2019-12-09 14:34:48
问题 Is it possible for the a.doStuff() method to print "B did stuff" without editing the A class? If so, how would I do that? class Program { static void Main(string[] args) { A a = new A(); B b = new B(); a.doStuff(); b.doStuff(); Console.ReadLine(); } } class A { public void doStuff() { Console.WriteLine("A did stuff"); } } class B : A { public void doStuff() { Console.WriteLine("B did stuff"); } } I'm modding a steam game, Terraria. And I don't want to decompile and recompile it all because

Implementing a method of interface is overriding or not in java

由 ╄→гoц情女王★ 提交于 2019-12-09 12:09:43
问题 I know this might be crazy but today one of my friend puzzled by asking when we implement an interface in java is it considered as method overriding. I told him it is not overriding as we are providing working(definition) of method first time when we implement any interface. To support multiple inheritance java provide interface but he was not convinced and was arguing. Please bring some light on to the topic. 回答1: The term "overriding" applies when there is an existing implementation of the

How to override external css?

由 两盒软妹~` 提交于 2019-12-09 12:07:55
问题 I have an external css file which applies 35px padding to my content div. All my html pages are loaded inside that div but for one of them I want to use 0 padding-right. I tried inline css, applying it directly on the body of that page and also using !important but nothing worked. What I am I doing wrong? index.html: <div id="content"><?php include "page.html"?></div> main.css: #content{ margin-top: 303px; padding: 35px; z-index:1; } page.html: <body style="padding:0px;"> 回答1: To override a

Override designated initializer of superclass

由 限于喜欢 提交于 2019-12-09 09:48:03
问题 I am reading a book which has a guideline: "If a class declares a designated initializer that is different from its superclass, the superclass’s designated initializer must be overridden to call the new designated initializer" As I understand this guideline in other words is that, if I am subclassing my class form its superclass, and my subclass has a designated initializer which is different from des. initializer of its superclass, then in my subclass I must override the designated

How to get a handle to an overriden built-in function? [duplicate]

由 情到浓时终转凉″ 提交于 2019-12-09 07:11:18
问题 This question already has an answer here : How to unhide an overriden function? (1 answer) Closed 6 years ago . On my Matlab path there's a custom zeros function. I want to store a handle to the built-in zeros in a variable. How can I do that? Thought about @(varargin)builtin('zeros',varargin{:}) , but this would probably slow down the operation due to the string comparison. Also, I've noticed that it's possible to refer to diag as @numel\diag , but this doesn't seem to work with other built

Extending Python's builtin Str

由 纵饮孤独 提交于 2019-12-09 04:13:18
问题 I'm trying to subclass str , but having some difficulties due to its immutability. class DerivedClass(str): def __new__(cls, string): ob = super(DerivedClass, cls).__new__(cls, string) return ob def upper(self): #overridden, new functionality. Return ob of type DerivedClass. Great. caps = super(DerivedClass, self).upper() return DerivedClass(caps + '123') derived = DerivedClass('a') print derived.upper() #'A123' print type(derived.upper()) #<class '__main__.DerivedClass'> print derived.lower(

Override identifier after destructor in C++11

由 寵の児 提交于 2019-12-09 04:04:54
问题 Does the override identifier after virtual destructor declaration have any special meaning? class Base { public: virtual ~Base() {} virtual int Method() const {} }; class Derived : public Base { public: virtual ~Derived() override {} virtual int Method() override // error: marked override, but does not override - missing const {} }; Using override identifier on virtual method is useful as check: compiler will report error when the Base virtual method is actualy not overriden. Does override on
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