While researching why the naive code in “Get links in page without using jQuery” wasn’t working I found out about Javascript’s HTMLCollection interface.

An HTMLCollection in the HTML DOM is live; it is automatically updated when the underlying document is changed.

HTMLCollection is very simple, as it has only 3 methods: length, item, and namedItem.

What I find interesting about it is that it’s live feature, as in it updates automatically.

Another interesting bit is the namedItem method, and the fact that doing


is the same as


And the same holds true for item.

Food for thoughts:

  • This item to [] sugar works in NodeList and Array too. How does Javascript make it possible?
  • Why is HTMLCollection defined as a Javascript interface instead of a type in the documentation page? Is it just a figure of speech or there is something different it the implementation?