Element.closest()

The closest() method traverses the Element and its parents (heading toward the document root) until it finds a node that matches the provided selector string. Will return itself or the matching ancestor. If no such element exists, it returns null.

var closestElement = targetElement.closest(selectors);

• selectors is a DOMString containing a selector list.
  ex: p:hover, .toto + q

• closestElement is the Element which is the closest ancestor of the selected element. It may be null.

• SyntaxError is thrown if the selectors is not a valid selector list string.

<article>
  <div id="div-01">Here is div-01
    <div id="div-02">Here is div-02
      <div id="div-03">Here is div-03</div>
    </div>
  </div>
</article>

var el = document.getElementById('div-03');

var r1 = el.closest("#div-02");
// returns the element with the id=div-02

var r2 = el.closest("div div");
// returns the closest ancestor which is a div in div, here it is the div-03 itself

var r3 = el.closest("article > div");
// returns the closest ancestor which is a div and has a parent article, here it is the div-01

var r4 = el.closest(":not(div)");
// returns the closest ancestor which is not a div, here it is the outmost article

For browsers that do not support Element.closest(), but carry support for element.matches() (or a prefixed equivalent, meaning IE9+), a polyfill exists:

if (!Element.prototype.matches) {
  Element.prototype.matches =
    Element.prototype.msMatchesSelector ||
    Element.prototype.webkitMatchesSelector;
}

if (!Element.prototype.closest) {
  Element.prototype.closest = function(s) {
    var el = this;

    do {
      if (Element.prototype.matches.call(el, s)) return el;
      el = el.parentElement || el.parentNode;
    } while (el !== null && el.nodeType === 1);
    return null;
  };
}

However, if you really do require IE 8 support, then the following polyfill will do the job very slowly, but eventually. However, it will only support CSS 2.1 selectors in IE 8, and it can cause severe lag spikes in production websites.

if (window.Element && !Element.prototype.closest) {
  Element.prototype.closest = function(s) {
    var matches = (this.document || this.ownerDocument).querySelectorAll(s),
        i,
        el = this;
    do {
      i = matches.length;
      while (--i >= 0 && matches.item(i) !== el) {};
    } while ((i < 0) && (el = el.parentElement));
    return el;
  };
}

• The Element interface.
• The syntax of Selectors
• Other methods that take selectors: element.querySelector() and element.matches().