Answers for "how to get an attribute of html with data- in js"

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);

html javascript data attributes

/* index.html
<div
  id="test-div"
  data-first-name="Tom"
  data-last-name="Mot"
  data-active
></div>
*/

// Reading
const div = document.getElementById("test-div");
console.log(div.dataset);
/*
{
  active: ""
  firstName: "Tom"
  lastName: "Mot"
}
*/

// Writing
const div = document.getElementById("test-div");
div.dataset.test = "Hello World!";
console.log(div.dataset.test); // Hello World