var element = document.querySelector('.element');
var dataAttribute = element.getAttribute('data-name');
// replace "data-name" with your data attribute name
console.log(dataAttribute);
Example 2: html javascript find data attribute
//javascript get html data attribute
const btns=document.querySelectorAll('button[data-id]');
[...btns].forEach(btn => console.log(btn.getAttribute('data-id')))
Example 3: javascript get data-id attribute
//get data-id attribute in plain Javascript
var element = document.getElementById('myDivID');
var dataID = element.getAttribute('data-id');
//get data-id using jQuery
var dataID = $('myDivID').data('data-id');
Example 4: get data attribute javascript
//
const el = document.querySelector('#element')
el.dataset.name // 'john'