how to add data atrributes to javscript code example

Example 1: js get data attribute

var element = document.querySelector('.element');
var dataAttribute = element.getAttribute('data-name');
// replace "data-name" with your data attribute name

console.log(dataAttribute);

Example 2: javascript get data attribute value

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