How to access object properties with special characters?

Question

I have a form DOM element:

var virDom = document.getElementsByTagName("form")[0];

virDom has two fields with IDs, namely creditId and pwdId... I can access virDom.creditId without issue, but virDom.pwdId.. causes a syntax error due to a period in the name.

How do I access a property like this?

Answer 1

Use square bracket notation:

virDom['creditId']
virDom['pwdId..']

This works for any object and is particularly useful for non-identifier safe characters and for accessing keys that may not be known in advance.