getter

How to override setter in Swift

由 情到浓时终转凉″ 提交于 2019-12-08 14:28:08
问题 A Superclass : class MySuperView : UIView{ var aProperty ; } A subclass inheritance the super class : class Subclass : MySuperClass{ // I want to override the aProperty's setter/getter method } I want to override the superclass's property's setter/getter method , how to override this method in Swift ? Please help me , thanks . 回答1: What do you want to do with your custom setter? If you want the class to do something before/after the value is set, you can use willSet / didSet : class

ES6 getter/method without curly braces

由 人盡茶涼 提交于 2019-12-07 07:41:42
问题 I have some classes which consist of many short getters/methods. Example: get jQuery() { return this.pageConfig.jQuery || jQuery; } An arrow function with similar content may be written as follows: () => this.pageConfig.jQuery || jQuery; Which is a one-liner and thus consumes only 1/3 of vertical space. But it is not a getter nor a method. Is there a recommended way of writing getters/methods in the form of a one-liner? (if possible without curly braces and without the return keyword) My

Is it a good idea to always return references for member variable getters?

由 南楼画角 提交于 2019-12-07 06:09:07
问题 If I have a class that has many int , float , and enum member variables, is it considered efficient and/or good practice to return them as references rather than copies, and return constant references where no changes should be made? Or is there a reason I should return them as copies? 回答1: There is no reason to return primitive types such as int and float by reference, unless you want to allow them to be changed. Returning them by reference is actually less efficient because it saves nothing

Kotlin val difference getter override vs assignment

由 蓝咒 提交于 2019-12-06 20:11:58
问题 I started playing arround with Kotlin and read something about mutable val with custom getter. As refered in e.g here or in the Kotlin Coding Convention one should not override the getter if the result can change. class SampleArray(val size: Int) { val isEmpty get() = size == 0 // size is set at the beginning and does not change so this is ok } class SampleArray(var size: Int) { fun isEmpty() { return size == 0 } // size is set at the beginning but can also change over time so function is

Java use getter in for loop or create a local variable? [duplicate]

由 跟風遠走 提交于 2019-12-06 19:41:17
问题 This question already has answers here : java how expensive is a method call (12 answers) Closed 3 years ago . I have a for loop which runs 4096 times and it should be as fast as possible. Performance is really important here. Currently I use getter methods inside the loop which just return values or objects from fields which don't change while the loop is in progress. Example: for (;;) { doSomething(example.getValue()); } Is there any overhead using getters? Is it faster using the following

Why is a simple get-statement so slow?

由 雨燕双飞 提交于 2019-12-06 19:13:59
问题 A few years back, I got an assignment at school, where I had to parallelize a Raytracer. It was an easy assignment, and I really enjoyed working on it. Today, I felt like profiling the raytracer, to see if I could get it to run any faster (without completely overhauling the code). During the profiling, I noticed something interesting: // Sphere.Intersect public bool Intersect(Ray ray, Intersection hit) { double a = ray.Dir.x * ray.Dir.x + ray.Dir.y * ray.Dir.y + ray.Dir.z * ray.Dir.z; double

How to read Action attributes from JSP fragments included with <jsp:include />?

由 不羁岁月 提交于 2019-12-06 15:54:11
Trying to call an Action's getter from an included JSP, I get null: MyAction.java private String message = "The message I want to read..."; public String getMessage() { return message; } main.jsp <%@taglib prefix="s" uri="/struts-tags" %> <html> <head></head> <body> <div> I'm a DIV in main.jsp </div> <jsp:include page="fragment.jsp" /> <body> </html> fragment.jsp <%@taglib prefix="s" uri="/struts-tags" %> <div> I'm a DIV from fragment.jsp <br/> Message from Action: <s:property value="message" /> </div> How can I get the attribute value in JSP fragment ? Use <s:include value="somePage.jsp">

C# array of properties

由 别等时光非礼了梦想. 提交于 2019-12-06 12:46:24
I have several get properties that I would like to be able to loop through like an array of functions. I would like to be able to do something like this public int prop1 { get; } public string prop2 { get; } public int[] prop3 { get; } public int prop4 { get; } public string prop5 { get; } public string prop6 { get; } Func<var> myProperties = { prop1, prop2, prop3, prop4, prop5, prop6 }; ArrayList myList = new ArrayList(); foreach( var p in myProperties) { myList.Add(p); } This code is very broken, but I think it conveys the idea of what I would like to be able to do. Anyone know how I can

How to pull a field from an object stored in an arraylist?

由 萝らか妹 提交于 2019-12-06 12:40:19
问题 Can I get some working code examples that I can pick apart and study how they work? Specifically, I need to figure out how do I get the address field from the x numbered object in my list? How do I delete the xth object from the list? How do I set the price field of object x to a new value? I understand how the houseList.add places the data into a new object that is appended to the end of the list, but I do not understand the converse of it and how to target a specific object and manipulate

Best practice since JavaFX setters/getters are final?

由 折月煮酒 提交于 2019-12-06 12:20:17
问题 In the process of converting a Windows application from Swing to JavaFX. We had a lot of custom components that previously overrode the mutator methods of JTextField, for example. In JavaFX these methods are declared final. Should I just be creating wrapper methods that call the final methods and modify the values before and after? I just want to make sure I go about doing it the right way from the beginning. Edit: I will also include the fact that some of this code is from much older
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