anonymous-function

问题 I've got a $.getJSON call in some code that appear to be not updating a global variable, and I'm at a loss to understand why. The JSON data is being loaded OK, but for some reason the global EventOptions array is not being updated in the for {} loop. The capitalised comments refer to the variable. Any ideas? Thanks function LoadMeasurementTypes() { // Clear out EventOptions EventOptions = ["..."]; // Push a couple on to EventOptions - THESE ADD OK EventOptions.push("Temperature");

问题 I have a Class A...in it's constructor...I am assigning an anonymous function to Object_B's eventHandler. How do I remove (unsubscribe) that from Dispose method of class A ? Any help would be appreciated ! Thanks Public Class A { public A() { B_Object.DataLoaded += (sender, e) => { Line 1 Line 2 Line 3 Line 4 }; } Public override void Dispose() { // How do I unsubscribe the above subscribed anonymous function ? } } 回答1: You can't, basically. Either move it into a method, or use a member

问题 In my continued effort to learn scala, I'm working through 'Scala by example' by Odersky and on the chapter on first class functions, the section on anonymous function avoids a situation of recursive anonymous function. I have a solution that seems to work. I'm curious if there is a better answer out there. From the pdf: Code to showcase higher order functions def sum(f: Int => Int, a: Int, b: Int): Int = if (a > b) 0 else f(a) + sum(f, a + 1, b) def id(x: Int): Int = x def square(x: Int):

问题 Is there a way of passing object context to an anonymous function without passing $this as an argument? class Foo { function bar() { $this->baz = 2; # Fatal error: Using $this when not in object context $echo_baz = function() { echo $this->baz; }; $echo_baz(); } } $f = new Foo(); $f->bar(); 回答1: You can assign $this to some variable and then use use keyword to pass this variable to function, when defining function, though I'm not sure if it is easier to use. Anyway, here's an example: class

问题 I would like to plot an function fx(y) = 3*y-y.^(3)-x with x being a parameter. I would like to graph fx(y) versus y for x varying over 0:0.5:6 all in one graph. For some reason it only works when you give x a single value and then use a anonymous function, but this is not what I need. x=@(y) 3.*y-y.^(3)-x; ezplot(fx) This gives me 3y-y^(3)-x = 0, but this is not what I need. I need to have a graph of fx versus y for the parameter x changing from 0 to 6 in steps of 0.5. This would give me

问题 i was working with anonymous functionss in erlang when a problem caught my attention. the function is defined as follows -module(qt). -export([ra/0]). ra = fun() -> 4 end. this however does not work -export(Ra/0]). Ra = fun() -> 4 end. and neither does this can anyone tell me why erlang exhibits this behaviour ? 回答1: An Erlang module cannot export variables, only functions. You can achieve something similar to exporting variables by exporting a function with zero arguments that simply returns

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: Calling closure assigned to object property directly Why this is not possible in PHP? I want to be able to create a function on the fly for a particular object. $a = 'a'; $tokenMapper->tokenJoinHistories = function($a) { echo $a; }; $tokenMapper->tokenJoinHistories($a); 回答1: With $obj->foo() you call methods, but you want to call a property as a function/method. This just confuses the parser, because he didn't

问题 I have a function, and would like to obtain its parameter types and return type for use in Scala macros. scala> val fn = (a: String, b: Double) => 123 fn: (String, Double) => Int = <function2> scala> fn.getClass res1: Class[_ <: (String, Double) => Int] = class $anonfun$1 In the above example, the parameter types and return type already get printed at both lines, but I don't know how to access them. Even with toString I'd be stuck with the <function2> and class $anonfun$1 parts right of the =

问题 Just set up a project using Android Studio 2.2.3 with Java 1.8 and Android 7 (API Level 24) trying to test the "new" java 8 feature Stream . Here my gradle file: apply plugin: 'com.android.application' android { compileSdkVersion 25 buildToolsVersion "25.0.2" defaultConfig { applicationId "com.example.radinator.myproject" minSdkVersion 24 targetSdkVersion 24 versionCode 1 versionName "1.0" testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" } buildTypes { release {

问题 I noticed in JQuery that the following code structure is used (function(){var l=this,g,y=l.jQuery,p=l.$,...})() Which seems to create a function, and call it. What is the benefit of taking this approach versus having the contents of the function inline? 回答1: It creates a closure to prevent conflicts with other parts of code. See this: http://docs.jquery.com/Plugins/Authoring Particularly handy if you have some other library that uses the $() method and you have to retain the ability to use