获取JavaScript中先前的同级锚元素的ID

Question

Solved : to get the id of the previous element, use previousElementSibling.id instead of previousSibling.id . Thank you to Xufox and Skyline3000 who quickly provided the solution.

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Having some breadcrumbs done of anchors elements, I'm trying to get the id of the previous sibling when one breakcrumb is clicked (ie the parent category). eg. Fruits> Apples> Green apples

Unfortunately, my code does not work.

• alert(this.previousSibling) returns [object Text]
• alert(this.previousSibling,id) returns id is undefined .
• alert(this.previousSibling,getAttribute(\\'id\\') returns TypeError: this.previousSibling.getAttribute is not a function .
• alert(this.previousSibling,attr(\\'id\\')) returns TypeError: this.previousSibling.attr is not a function .

I assume that the sibling is not correctly reached as I was expecting some Element or Object and not Text.

Here's what the HTML and javascript of two breadcrumbs look like:

<a id="n5_40_64_40" onclick="javascript:
    var tree=jQuery('#tree').dynatree('getTree');
    if (!tree.activateKey('40')) {
      var parent=0;
      if (1) {
       parent=this.previousSibling.id.split(/[_]+/).pop();
      }
    }
    return false;" href="">Apples</a>
>
<a id="n5_40_64_64" onclick="javascript:
    var tree=jQuery('#tree').dynatree('getTree');
    if (!tree.activateKey('64')) {
      var parent=0;
      if (2) {
       parent=this.previousSibling.id.split(/[_]+/).pop();
      }
    }
    return false;" href="">Green apples</a>

Answer 1

All text and whitespace, including whitespace and new lines between your HTML tags, count as a TextNode . Thus the tag's previous sibling is actual the textNode of whitespace between the <a> tags. What you really want to do is find the previous sibling that is an element (HTML tag).

For that you should simply use this.previousElementSibling .