84669 person learning
152542 person learning
20005 person learning
5487 person learning
7821 person learning
359900 person learning
3350 person learning
180660 person learning
48569 person learning
18603 person learning
40936 person learning
1549 person learning
1183 person learning
32909 person learning
How to get it? These p's are all sibling elements. How to get the sequence number of one of these p's?
<p</p>//序号0 <p</p>//序号1 <p</p>//序号2 <p</p>//序号3 <p</p>//序号4
function index(el) { return Array.prototype.indexOf.call(el.parentElement.children, el) }
Read in a loop through the prevSiblings of the element, and read a count+1 until no more is read. The final count is the index
Determine how many nodes there are in front of a certain p, and add one for each additional serial number, until there is no node in front, and then the serial number value of the current node is obtained
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Read in a loop through the prevSiblings of the element, and read a count+1 until no more is read. The final count is the index
Determine how many nodes there are in front of a certain p, and add one for each additional serial number, until there is no node in front, and then the serial number value of the current node is obtained