Read doctype with JavaScript

Is the doctype part of the DOM, and if so, is there a go开发者_如何学Good cross-browser way to read it? I'm not trying to do anything fancy. I just want to access the doctype information from within some JavaScript code. Read-only access is fine.

document.doctype seems to be the (read-only) property you're looking for.

If you're inspecting the DOCTYPE to determine if you're in quirksmode or not, this is known to be cross-browser:

document.compatMode; // returns either "BackCompat" or "CSS1Compat"

So you can do:

var quirksmode = document.compatMode == "BackCompat";