Is there a JavaScript solution to generating a “table of contents” for a page?

Question

I have headers in

through

tags. Is there a way that I can use JavaScript to generate a table of contents for the contents tha

Answer 1

  this.insert = (el, h) => {
    let li = document.createElement('li');
    li.innerText = h.innerText;
    li.setAttribute('tagName', h.tagName);
    if(el.tagName == 'OL') {
      el.appendChild(li);
      return li;
    } else if(el.getAttribute('tagName') < h.tagName) {
      let ol = el.children.length > 0 ? ol = el.querySelector('ol') : document.createElement('ol');
      ol.appendChild(li);
      el.appendChild(ol);
      return li;
    } else if(!el.parentNode.parentNode) {
      el.parentNode.appendChild(li);
      return li;
    } else {
      return this.insert(el.parentNode.parentNode, h);
    }
  }

  this.parse = (headers) => {
    let list = document.createElement('ol');
    let el = list;
    for(i=0; i