使用另一个元素的内容创建和附加一个 DOM 元素

Question

我的代码如下

  ;(function(window){
    var $description_window= document.querySelector('.mg_post_description'),
        $headings= document.querySelectorAll('.mg_blog_main_content h3'),
        $paragraph = document.createElement('p');
        for (var j = 0; j < $headings.length; j++) {
            var $headingChildren=$headings[j].cloneNode(true).childNodes;
            $paragraph.appendChild($headingChildren[j]);
       }
       $description_window.append($paragraph);
})(window);

这里我想做的是；复制内容框的 h3 标签。然后创建一个paragraph 元素。然后将p 标记附加到收集的h3 标记中。但是，运行此程序时出现以下错误。

在Node 上执行appendChild 失败：参数1 不是Node 类型。

  ;(function(window){
    var $description_window= document.querySelector('.post_description'),
    
   $headings= document.querySelectorAll('.post_description h3'),
   $paragraph = document.createElement('p');
   
   for (var j = 0; j < $headings.length; j++) {
   
       var $headingChildren=$headings[j].cloneNode(true).childNodes;
            $paragraph.appendChild($headingChildren[j]);
       }
       
       $description_window.append($paragraph);
       
})(window);

.post_description{

  width:200px;
  height:200px;
  background-color:#555;
  position:absolute;
  top:10%;
  right:8%;
  
}

.post_description a {
  
  color:white;
}

.main_body{

  padding-top:40%;

}

<div class="main_body">
    <h3>Testing one</h3>
  <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>

  <h3>Testing two</h3>
  <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>


  <h3>Testing three</h3>

  <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>


  <h3>Testing four</h3>

  <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>

</div>

<div class="post_description"></div>

有人能解释一下为什么会发生这种情况以及如何解决这个问题

谢谢

Answer 1

var d = document.querySelector('.desc'),
    h = document.querySelectorAll('.main h3');

h.forEach(function(n) {
  var p = document.createElement('p');
  p.innerHTML = n.cloneNode(true).innerHTML || '';
  d.append(p);
});

.desc {
  color: red;
}

<div class="main">
  <h3>First</h3>
  <h3>Second</h3>
  <h3>Third</h3>
</div>

<div class="desc">
</div>

Answer 2

要达到预期效果，请使用以下选项

function addElem() {
    var mElem = document.querySelector('.mg_post_description')
    var hElems = document.getElementsByTagName('H3');
    var node = document.createElement("P");
    for (var i = 0; i < hElems.length; i++) {

        var textnode = document.createTextNode(hElems[i].innerHTML);
        var cloneElem = node.cloneNode(true);
        cloneElem.appendChild(textnode);
        mElem.appendChild(cloneElem);
    }
};

addElem()

Codepen-https://codepen.io/nagasai/pen/YVEzdJ