JavaScript的一些注意事项原创邦

JavaScript的一些注意事项

There are a number of issues involved with getting scripts to load at the right time.
involved with 投入到，卷入到

There are a number of issues that involved with getting scripts to load at the right time.
很多问题都是脚本加载的时机问题。
很多问题都是涉及到脚本加载的时间。
需要在正确的时间加载脚本引起了很多问题。

involved这个词很神奇。

例子来自：https://developer.mozilla.org/en-US/docs/Learn/JavaScript/First_steps/What_is_JavaScript

document.addEventListener("DOMContentLoaded", function() {
  function createParagraph() {
    let para = document.createElement('p');
    para.textContent = 'You clicked the button!';
    document.body.appendChild(para);
  }

  const buttons = document.querySelectorAll('button');

  for(let i = 0; i < buttons.length ; i++) {
    buttons[i].addEventListener('click', createParagraph);
  }
});

错误的示例

document.addEventListener("DOMContentLoaded", function() {
  function createParagraph() {
    let para = document.createElement('p');
    para.textContent = 'You clicked the button!';
    document.body.appendChild(para);
  }

  const buttons = document.querySelectorAll('button');

  for(let i = 0; i < buttons.length ; i++) {
    buttons[i].addEventListener('click', createParagraph());
  }
});

注意前后两段代码区别是加粗的 createParagraph 和 createParagraph(), 后面的多了一个()

It is bad practice to pollute your HTML with JavaScript, and it is inefficient--you'd have to include the

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发布于: 2021-08-18
修改于: 2021-08-18