data-id html javascript
<div id='strawberry-plant' data-fruit='12'></div>
<script>
// 'Getting' data-attributes using getAttribute
var plant = document.getElementById('strawberry-plant');
var fruitCount = plant.getAttribute('data-fruit'); // fruitCount = '12'
// 'Setting' data-attributes using setAttribute
plant.setAttribute('data-fruit','7'); // Pesky birds
</script>
Smoggy Skylark