What I want to achieve here is to display the value of the index of < li >< /li > (under < ol >< /ol > default type) to the < p >< /p >(could be one of more, most likely just one) inside it.
MY INITIAL CODE:
<ol>
<li>
<p>First p element in div.</p>
</li>
<li>
<span>Second p</span>
</li>
<li>
<p>A third p element in div.</p>
</li>
<li>
<p>A fourth p element in div.</p>
</li>
</ol>
SCRIPT:
<script>
var x = document.getElementsByTagName('li');
var y = document.getElementsByTagName('p');
for(var j = 0; j < x.length; j++){
for(var k = 0; k < y.length; k++) {
if(x[j].index == y[k].index){
y[j].innerHTML = j+1;
}
}
}
</script>
OUTPUT:
1.1
2.Second p
3.2
4.3
EXPECTED OUTPUT:
1.1
2.Second p
3.3
4.4
In your code, both x[j].index and y[k].index are undefined. What do you expect to happen when this occurs?
I recommend using querySelectorAll
instead of getElementsByTagName
- more precise. Then don't get all p
elements in the document; just get all p
elements in each li
. Probably a more elegant way to do this but the nested loop approach works:
var li = document.querySelectorAll('ol li'); for(var i = 0; i < li.length; i++) { var p = li[i].querySelectorAll('p'); for(var j = 0; j < p.length; j++) { p[j].innerHTML = i + 1; } }
<ol> <li> <p>First p element in div.</p> </li> <li> <span>Second p</span> </li> <li> <p>A third p element in div.</p> </li> <li> <p>A fourth p element in div.</p> </li> </ol>
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.