referenceerror

问题 I've started learning QML recently (after trying it out a long time ago) and I'm stuck at the way Qt C++ code interacts with QML and vice versa. I have a Counter which has the following header: #include <QObject> #include <QTimer> class Counter : public QObject { Q_OBJECT Q_PROPERTY(int count READ getCount WRITE setCount NOTIFY signalCountChanged) public: Counter(QObject *parent = Q_NULLPTR); int getCount(); void setCount(int count); signals: void signalCountChanged(int); public slots: void

问题 I’m trying to wrap my head around the behavior of reference errors thrown in JavaScript. In the following example, a ReferenceError is thrown at the second line, and execution breaks: var obj = {}; obj.func1 = func2; alert('Completed'); Whereas in this example, the code completes successfully, though obj.func1 remains undefined : var obj = {}; obj.func1 = func2; var func2 = function() { alert('func2'); }; alert('Completed'); My assumption was that an error would be thrown at the second line

问题 In javascript window is the global object, which means every object in the global scope is a child of window . So why I get this result: console.log(window.foo); // No error, logs "undefined". console.log(foo); // Uncaught ReferenceError: foo is not defined. Fiddle Those two lines should be the same, shouldn't they? 回答1: Because with window.foo you are explicitly looking for foo property of window object which is not the case in latter option. In the latter option, if foo isn't defined, you

问题 Getting an error when creating a Foundation Zurb project. Tried to solve using the previous suggestions shown for other applications, but none are working. A post referenced updating elm, and I did so, however, it did not work. Additionally, I reviewed the closed issue for Gulp 3 (i am using gulp 4), but there was not viable fixes (Gulp 3 is broken on Node 12 #2324) or workarounds. $ foundation new --framework emails fs.js:27 const { Math, Object } = primordials; ^ ReferenceError: primordials

问题 my english is poor, my apology for this :) I have a problem with angular 2. I would create a login form but after call web service and get response I had this error below. To blocked and authorized user on my app I'm based on auth-guard.service.ts of angular tutorial. This error came after the canLoad action on my routing. I use angular 2 latest version, my project is based on webpack. My package.json configuration is : "dependencies": { "@angular/common": "~2.1.1", "@angular/compiler": "~2.1

问题 How come this code throws an Uncaught ReferenceError: $ is not defined when it was OK before? $(document).ready(function() { $('#tabs > ul').tabs({ fx: { opacity: 'toggle' } }); $('#featuredvid > ul').tabs(); }); Results in tabs don't close anymore. jQuery is referenced in the header: <script language="JavaScript" type="text/javascript" src="<?php echo get_option('siteurl') ?>/js/sprinkle.js"></script> <script language="JavaScript" type="text/javascript" src="<?php echo get_option('siteurl')

问题 I am using Vanilla Masonry (the raw JS, non-jQuery version) as follows: In head: <script id="masonry" type="text/javascript" src="resources/js/masonry.js"></script> In body: <script> window.onload = function() { var wall = new Masonry( document.getElementById('ext-component-3'), { columnWidth: 145 }); }; </script> But I keep getting: Uncaught ReferenceError: Masonry is not defined Uncaught TypeError: Cannot call method 'appendChild' of undefined Does anyone know what could be wrong in my

问题 I get a ReferenceError in the following userscript code: // ==UserScript== // @name ... // @namespace ... // @description ... // @include ... // @grant GM_xmlhttpRequest // ==/UserScript== console.log(GM_info); try { console.log(GM_xmlhttpRequest({ method: "GET", url: "http://google.ca/", synchronous: true }).readyState); } catch (e) { console.log(e); } ... It first logs GM_info successfully, then logs the ReferenceError. (I'm using Firefox/Firebug.) ReferenceError: GM_xmlhttpRequest is not

问题 I have a simple javascript package I'm trying to test. I want to check for an Error being thrown, but when my test is run, and the error is thrown, the test is marked as failing. Here's the code: var should = require('chai').should(), expect = require('chai').expect(); describe('#myTestSuite', function () { it ('should check for TypeErrors', function () { // Pulled straight from the 'throw' section of // http://chaijs.com/api/bdd/ var err = new ReferenceError('This is a bad function.'); var

问题 In Chrome's JavaScript console, if I run this: var that = new XMLHttpRequest(); that.open('GET', 'http://this_is_a_bad_url.com', false); that.send(); I get an intentionally expected error: NetworkError: A network error occurred. I want to catch this, so I use: var that = new XMLHttpRequest(); that.open('GET', 'http://this_is_a_bad_url.com', false); try { that.send(); } catch(exception) { if(exception instanceof NetworkError) { console.log('There was a network error.'); } } However, I get an