html dom forms object as array in js

[ala888]

if the html dom object forms exists in javascript as an object,

why can its contents be called as if it were an array?

 

documents.forms[0]....

 

I appreciate the help!

[Ingolme]

There are certain data types called NodeList or HTMLCollection that the browser uses in the DOM, it can be accessed like if it was an array but it is an object. getElementsByTagName() and many other DOM methods also return a NodeList which behaves the same way.

 

You can't create objects like that using Javascript, it is something the browser does internally. Technically, the [] notation is not official, the specification says to use the item() method instead: document.getElementsByTagName("a").item(0);