学习JavaScript承诺只需要一些方向

I am Learning JavaScript Promises and I just wanted to know if the following code is correct. Basically it's very simple. Loads a script file. If the file can't be loaded there there is a error.

我正在学习JavaScript承诺，我只是想知道以下代码是否正确。基本上它很简单。加载脚本文件。如果无法加载文件，则会出错。

var promise = new Promise((resolve, reject) => {

  var fh = document.createElement('script');
  fh.type = 'text/javascript';
  fh.async = true;
  fh.src = 'script.js';

  /*Insert javascript at top of dom */
  fhs.parentNode.insertBefore(fh, fhs);


  /*Success Response */
  fh.addEventListener('load', function (event) {

    resolve('Loaded');

  }, false);


  /*Error Response */
  fh.addEventListener("error", function (event) {

    reject(Error('Error loading file'));

  }, false);
});

1 个解决方案

#1

You have a typo.

你有一个错字。

fhs.parentNode.insertBefore(fh, fhs);

fhs is not defined. Where is it supposed to come from? The console would have caught this error for you. Instead, you can append the script element to the body.

fhs没有定义。它应该来自哪里？控制台会为您捕获此错误。相反，您可以将脚本元素附加到正文。

var promise = new Promise((resolve, reject) => {

  var fh = document.createElement('script');
  fh.async = true;
  fh.src = 'script.js';

  /*Insert javascript at bottom of dom */
  document.body.appendChild(fh);  

  /*Success Response */
  fh.addEventListener('load', () => resolve('Loaded'));

  /*Error Response */
  fh.addEventListener("error", () => reject(Error('Error loading file')));

});

1 个解决方案

#1

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