JAVASCRIPT

js get custom attribute

document.getElementById("divId").getAttribute("attributeId");

javascript get element by custom attribute

document.querySelector("div[data-automation='something']")

Select element by custom attribute

javascript get custom attribute value from element

<!-- TRYING TO ACCESS TO CUSTOM ATTRIBUTES WITH JAVASCRIPT ? -->

<article
  id="electric-cars"
  data-columns="3"
  data-index-number="12314"
  data-parent="cars">
</article>

<script>
// const article = document.getElementById("electric-cars")
article.dataset.columns // "3"
article.dataset.indexNumber // "12314"
article.dataset.parent // "cars"
</script>