var element = document.querySelector('.element');
var dataAttribute = element.getAttribute('data-name');
// replace "data-name" with your data attribute name
console.log(dataAttribute);<div data-myvar="hello world"</div>
<script>
//Note: attribute in html will force lowercase, make sure all letters are lower
var element = document.querySelector("div");
console.log(element.dataset.myvar);
//outputs: hello world
</script>const article = document.querySelector('#electric-cars');
article.dataset.columns // "3"
article.dataset.indexNumber // "12314"
article.dataset.parent // "cars"