Element.getAttributeNames()

The getAttributeNames() method of the Element interface returns the attribute names of the element as an Array of strings. If the element has no attributes it returns an empty array.

Using getAttributeNames() along with getAttribute(), is a memory-efficient and performant alternative to accessing Element.attributes.

let attributeNames = element.getAttributeNames();

// Iterate over element's attributes
for (let name of element.getAttributeNames()) {
  let value = element.getAttribute(name);
  console.log(name, value);
}

if (Element.prototype.getAttributeNames == undefined) {
  Element.prototype.getAttributeNames = function () {
    var attributes = this.attributes;
    var length = attributes.length;
    var result = new Array(length);
    for (var i = 0; i < length; i++) {
      result[i] = attributes[i].name;
    }
    return result;
  };
}