未捕获的TypeError：无法在php脚本中读取未定义的属性'parentNode'

Question

我的脚本在下面给出错误

  

未捕获的TypeError：无法读取未定义的属性“parentNode”

<script>
     (function(d, s, id) {
    var js, fjs = d.getElementsByTagName[0];
    if (d.getElementById(id)) return;
    js = d.createElement; js.id = id;
    js.src = "https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v2.6";
    fjs.parentNode.insertBefore(js,fjs);
  }(document, 'script', 'facebook-jssdk'));
  </script>

查看部分是       

  <blockquote cite="url">
    <a href="url"></a>
  </blockquote>
</div>

Answer 1

使用tagName函数时需要传递getElementsByTagName()，因此请使用

fjs = d.getElementsByTagName(s)[0]

而不是

fjs = d.getElementsByTagName[0]

Answer 2

<script>
 (function(document, s, id) {
 let js;
const id = id;
const ref = document.getElementsByTagName('script')[0];

if (document.getElementById(id)) {
  return;
}

js = document.createElement('script');
js.id = id;
js.async = true;
js.src = '//connect.facebook.net/en_US/sdk.js';

ref.parentNode.insertBefore(js, ref);
}(document, 'script', 'facebook-jssdk'));
</script>

Answer 3

更改版本

<script>
 (function(d, s, id) {
var js, fjs = d.getElementsByTagName[0];
if (d.getElementById(id)) return;
js = d.createElement; 
js.id = id;
js.src = 'https://connect.facebook.net/en_US/sdk.js#xfbml=1&amp;version=v2.5';
fjs.parentNode.insertBefore(js,fjs);

}（文档，＆＃39;脚本＆＃39;，＆＃39; facebook-jssdk＆＃39;））;