我使用Node JS进行web应用程序开发。我在require()模块中有一个混乱。我需要一个位于file_handler目录中的JS文件。以下两种情况之间的区别是什么?
//在server.js中
var chat = require("./file_handler/chat.js"); // Does not work
或
var chat = require("./file_handler/chat.js")(); // It works
为什么额外的括号在语句的最后?
Error: core.js:6210 ERROR TypeError: You provided 'undefined' where a stream was expected. You can provide an Observable, Promise, Array, or Iterable.
at subscribeTo (subscribeTo.js:27)
at innerSubscribe (innerSubscribe.js:71)
at MergeMapSubscriber._innerSub (mergeMap.js:57)
at MergeMapSubsc
为什么会抛出这个错误?从模块类中调用外部(全局作用域)函数的正确方式是什么? //models.js
export default class Model {
log() {
gLog(); //Uncaught ReferenceError: gLog is not defined
}
}
//main.js
import Model from './models.js';
let m = new Model();
m.log();
function gLog() {
console.log(1);
}
悬而未决的问题。查看Global (gtag.js)片段,我并不真正理解arguments变量的使用。
<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=GA_TRACKING_ID"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){d
Rails应用,学习CoffeeScript和Backbone.js:
Uncaught TypeError: Cannot use 'in' operator to search for 'id' in easy
_.extend.setbackbone.js:205
Backbone.Modelbackbone.js:142
Gamegames.js:13
(anonymous function)games.js:34
jQuery.Callbacks.firejquery.js:1047
jQuery.Callbacks.self.fireWithjque