Answers for "store data in html attribute as a number"

get data attribute javascript

// <div id="element" data-name="john"></div>

const el = document.querySelector('#element')
el.dataset.name // 'john'

javascript get data attribute value

const article = document.querySelector('#electric-cars');
 
article.dataset.columns // "3"
article.dataset.indexNumber // "12314"
article.dataset.parent // "cars"