IE8 does not support querySelectorAll

Question

I tried to use document.querySelectorAll(), but IE8 throw error, that

Object doesn\'t support this property or method

Answer 1

IE8 only supports querySelectorAll() in standards mode. From MSDN:

The Selectors API is defined as part of the Selectors API specification and is only available to Web pages displayed in IE8 standards mode.

Chances are your page doesn't have a proper DOCTYPE declaration; you will need to add one.