How to highlight columns in a table depending on thead?

Question

JavaScript

example on jsfiddle https://jsfiddle.net/KLON/z0dxus7w/1/
if thdead last name has a class, how to highlight names? html markup can only be changed for thead , tbody must be css or jquery

Answer 1

const $table = $('table');
const indices = $table.find('thead .red').get().map((n, i) => $(n).index());

$table
  .find('tbody tr')
  .each((_, n) => $('td', n).filter(i => indices.includes(i)).addClass('red'));