overriding

Can I override a property in c#? How?

由 ≡放荡痞女 提交于 2019-11-26 13:22:06
问题 I have this Base class: abstract class Base { public int x { get { throw new NotImplementedException(); } } } And the following descendant: class Derived : Base { public int x { get { //Actual Implementaion } } } When I compile I get this warning saying Derived class's definition of x is gonna hide Base's version of it. Is is possible to override properties in c# like methods? 回答1: You need to use virtual keyword abstract class Base { // use virtual keyword public virtual int x { get { throw

Understanding the purpose of Abstract Classes in Java

由 青春壹個敷衍的年華 提交于 2019-11-26 13:08:15
问题 Suppose I have two Classes, A and B. The A class is defined as abstract, while B extends this abstract class, and finally i test the result and both classes are part of same package. public abstract class A { protected abstract void method1(); protected void method2() { System.out.println(\"This is Class A\'s method\"); } } public class B extends A { @Override protected void method1() { System.out.println(\"This is B\'s implementaiton of A\'s method\"); } } and now when i test them: B b = new

'Shadows' vs. 'Overrides' in VB.NET

由 爷，独闯天下 提交于 2019-11-26 12:54:54
问题 What is the significance of the two keywords Shadows and Overrides? What they do and for which context is one or the other preferable? 回答1: I wouldn't consider Shadows to really be an OOP concept. Overrides indicates that you are providing new or additional functionality for a method/property etc that was declared in an ancestor class. Shadows really tricks the compiler into thinking that the parent method/property etc does not even exist. I have no use for Shadows. Stick to Overrides. These

Why doesn't the compiler complain when I try to override a static method?

由 对着背影说爱祢 提交于 2019-11-26 12:25:48
问题 I know that we cannot override static methods in Java, but can someone explain the following code? class A { public static void a() { System.out.println(\"A.a()\"); } } class B extends A { public static void a() { System.out.println(\"B.a()\"); } } How was I able to override method a() in class B ? 回答1: You didn't override anything here. To see for yourself, Try putting @Override annotation before public static void a() in class B and Java will throw an error. You just defined a function in

How do I override a Python import?

由 淺唱寂寞╮ 提交于 2019-11-26 12:11:15
问题 I\'m working on pypreprocessor which is a preprocessor that takes c-style directives and I\'ve been able to make it work like a traditional preprocessor (it\'s self-consuming and executes postprocessed code on-the-fly) except that it breaks library imports. The problem is: The preprocessor runs through the file, processes it, outputs to a temporary file, and exec() the temporary file. Libraries that are imported need to be handled a little different, because they aren\'t executed, but rather

How to override to_json in Rails?

由 醉酒当歌 提交于 2019-11-26 12:03:00
Update: This issue was not properly explored. The real issue lies within render :json . The first code paste in the original question will yield the expected result. However, there is still a caveat. See this example: render :json => current_user is NOT the same as render :json => current_user.to_json That is, render :json will not automatically call the to_json method associated with the User object. In fact , if to_json is being overridden on the User model, render :json => @user will generate the ArgumentError described below. summary # works if User#to_json is not overridden render :json =

Android @Override usage [duplicate]

由 天涯浪子 提交于 2019-11-26 11:59:34
问题 This question already has answers here : When do you use Java's @Override annotation and why? (27 answers) Closed 10 months ago . (Newbie to Java, old time C# guy.) I have noticed a lot of the use of @Override in Android example code. I thought that all Java methods were by default \"Virtual\"? What then does @Override do? Example: private class HelloWebViewClient extends WebViewClient { @Override public boolean shouldOverrideUrlLoading(WebView view, String url) { view.loadUrl(url); return

Differentiate between function overloading and function overriding

由 橙三吉。 提交于 2019-11-26 11:57:56
问题 Differentiate between function overloading and function overriding in C++? 回答1: You are putting in place an overloading when you change the original types for the arguments in the signature of a method. You are putting in place an overriding when you change the original definition of a method. 回答2: Overloading a method (or function) in C++ is the ability for functions of the same name to be defined as long as these methods have different signatures (different set of parameters). Method

maven command line how to point to a specific settings.xml for a single command?

由 混江龙づ霸主 提交于 2019-11-26 11:55:15
问题 Is it possible to point to a specific settings file in order to override the default settings.xml being used by maven for a single command? Example: mvn clean install -Dparam # -> pass specific settings file path as param to override default \"home/.m2/settings.xml\" 回答1: You can simply use: mvn --settings YourOwnSettings.xml clean install or mvn -s YourOwnSettings.xml clean install 来源： https://stackoverflow.com/questions/25277866/maven-command-line-how-to-point-to-a-specific-settings-xml-for

The difference between virtual, override, new and sealed override

由 早过忘川 提交于 2019-11-26 11:49:47
问题 I\'m pretty confused between some concepts of OOP: virtual , override , new and sealed override . Can anyone explain the differences? I am pretty clear that if the derived class method is to be used, one can use the override keyword so that the base class method will be overriden by derived class. But I\'m not sure about new , and sealed override . 回答1: The virtual keyword is used to modify a method, property, indexer or event declaration, and allow it to be overridden in a derived class. For
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