I am a pretty novice javascript user. I need some help debugging this code. What I intend this to do is based on the amount of values in the list, is create a 3 column wide table to display each. BTW the whole html formatting is set up with grid.
The error is:
Uncaught TypeError: Cannot read properties of undefined (reading ‘appendChild’)
HTML (inside body):
<section id="db_gallery">
<table id="gallery_table"></table>
<script src="autogallery.js"></script>
</section>
JS in autogallery.js:
const gallery_table = document.getElementById("gallery_table");
const list = ["A", "B", "C", "D", "E", "F"];
for (let i of list) {
if (i % 3 === 0) {
let newRowItem = document.createElement("tr");
var idName = "newRowItem";
idName.concat(i);
newRowItem.setAttribute("id", idName);
gallery_table.appendChild(newRowItem);
}
let newColItem = document.createElement('th');
newColItem.textContent = i;
idName.appendChild(newColItem);
console.log(idName);
}
Also it would be a big help if any suggestions were simple to understand. If it means anything I will eventually be linking this to a phpmyadmin database as the values in the array.
Thanks!
3
Answers
Try
instead of
First you should
newRowItem.appendChild
instead ofidName
becausenewRowItem
is the element you’ve created.And second when using
for...of
i
is the element not the index, so it’s better to usefor
in your case.And last you shouldn’t use
newRowItem
outside the scope because you declared it withlet
insideif
caluse.this should be correct:
Use for loop with index to do modulo operation on list indexes.