overriding

Overriding equals() & hashCode() in sub classes … considering super fields

由 泪湿孤枕 提交于 2019-11-27 05:08:59
问题 Is there a specific rule on how Overriding equals() & hashCode() in sub classes considering super fields ?? knowing that there is many parameters : super fields are private/public , with/without getter ... For instance, Netbeans generated equals() & hashCode() will not consider the super fields ... and new HomoSapiens("M", "80", "1.80", "Cammeron", "VeryHot").equals( new HomoSapiens("F", "50", "1.50", "Cammeron", "VeryHot")) will return true :( public class Hominidae { public String gender;

Overriding static variables when subclassing

由 筅森魡賤 提交于 2019-11-27 05:01:59
I have a class, lets call it A, and within that class definition I have the following: static QPainterPath *path; Which is to say, I'm declaring a static (class-wide) pointer to a path object; all instances of this class will now have the same shared data member. I would like to be able to build upon this class, subclassing it into more specialised forms, layering behaviour, and with each class having its own unique path object (but not having to repeat the boring bits like calculating bounding boxes or calling the painting routines). If I subclass it to create a class F (for example), I want

Perplexing output in Java with inheritance and overriding methods

由 寵の児 提交于 2019-11-27 04:44:06
问题 I stumbled upon this piece of code. I tried to guess what will be the result of running it before actually doing so. I was really confused when I saw them & in need of some explanations. This is the code: public class A { String bar = "A.bar"; A() { foo(); } public void foo() { System.out.println("A.foo(): bar = " + bar); } } public class B extends A { String bar = "B.bar"; B() { foo(); } public void foo() { System.out.println("B.foo(): bar = " + bar); } } public class C { public static void

Delphi subclass visual component and use it

由 可紊 提交于 2019-11-27 04:43:13
问题 I would like to subclass TToolBar with another class called MyTToolBar so that I can override a method. I'm new to Delphi, but after two hours of trying various methods, I can't get MyTToolBar to be used instead of TToolBar. I can't be the first person who's wanted to override a method on a visual component class. I come more from an Xcode background where subclassing a visual component is easy. You create a subclass (e.g., MySubclass) of a parent class (e.g., MySuperClass) and then just

C#: Overriding OnPaint on ProgressBar not working?

由 烈酒焚心 提交于 2019-11-27 04:40:28
问题 Was thinking it should be pretty easy to create a ProgressBar that drew some text upon itself. However, I am not quite sure what is happening here... I added the following two overrides: protected override void OnPaintBackground(PaintEventArgs pevent) { base.OnPaintBackground(pevent); var flags = TextFormatFlags.VerticalCenter | TextFormatFlags.HorizontalCenter | TextFormatFlags.SingleLine | TextFormatFlags.WordEllipsis; TextRenderer.DrawText(pevent.Graphics, "Hello", Font, Bounds, Color

Globally override malloc in visual c++

由 混江龙づ霸主 提交于 2019-11-27 04:35:09
问题 I'm trying to figure out a way to globally override malloc and related functions in visual c++ (2005). My setup is a dll with statically linked runtime library that consists of both my own c++ code, external c++ and c code. What I want to accomplish is to allow a user of the dll to set their own implementations of the memory allocation functions. Solutions that I can't use: Overriding new and delete globally, there is lots of external C libraries in my code base which means this won't capture

Can a static method be overridden in C#?

由 女生的网名这么多〃 提交于 2019-11-27 04:28:42
I was told that static methods are implicitly final and therefore can't be overridden. Is that true? Can someone give a better example of overriding a static method? If static methods are just class methods, what is the real use of having them? (1) Static methods cannot be overridden, they can however be hidden using the 'new' keyword. Mostly overriding methods means you reference a base type and want to call a derived method. Since static's are part of the type and aren't subject to vtable lookups that doesn't make sense. E.g. statics cannot do: public class Foo { public virtual void Bar() {

Javascript: Overriding XMLHttpRequest.open()

由 ╄→尐↘猪︶ㄣ 提交于 2019-11-27 04:23:05
问题 How would I be able to override the XMLHttpRequest.open() method and then catch and alter it's arguments? I've already tried the proxy method but it didn't work, although removing the open over-rid when XMLHttpRequest() was called: (function() { var proxied = window.XMLHttpRequest.open; window.XMLHttpRequest.open = function() { $('.log').html(arguments[0]); return proxied.apply(this, arguments); }; })(); 回答1: You are not modifying the open method inherited by XMLHttpRequest objects but just

Overriding a stored property in Swift

由 我怕爱的太早我们不能终老 提交于 2019-11-27 04:21:29
问题 I noticed that the compiler won't let me override a stored property with another stored value (which seems odd): class Jedi { var lightSaberColor = "Blue" } class Sith: Jedi { override var lightSaberColor = "Red" // Cannot override with a stored property lightSaberColor } However, I'm allowed to do this with a computed property: class Jedi { let lightSaberColor = "Blue" } class Sith: Jedi { override var lightSaberColor : String{return "Red"} } Why am I not allowed to give it another value?

Java: Calling a super method which calls an overridden method

由 早过忘川 提交于 2019-11-27 03:57:42
问题 public class SuperClass { public void method1() { System.out.println("superclass method1"); this.method2(); } public void method2() { System.out.println("superclass method2"); } } public class SubClass extends SuperClass { @Override public void method1() { System.out.println("subclass method1"); super.method1(); } @Override public void method2() { System.out.println("subclass method2"); } } public class Demo { public static void main(String[] args) { SubClass mSubClass = new SubClass();
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