HTML 5 test for new elements

How can I test if my browser supports the new semantic HTML 5 elements like:

<nav>
<foo开发者_开发知识库ter>

and so on?

Dive Into HTML5 > Detecting HTML5 Features:

There are four basic techniques for detecting whether a browser supports a particular feature. From simplest to most complex:

1. Check if a certain property exists on a global object (such as window or navigator).

   Example: testing for geolocation support

2. Create an element, then check if a certain property exists on that element.

   Example: testing for canvas support

3. Create an element, check if a certain method exists on that element, then call the method and check the value it returns.

   Example: testing which video formats are supported

4. Create an element, set a property to a certain value, then check if the property retained its value.

   Example: testing which <input> types are supported

Also, there is

Modernizr, an open source, MIT-licensed JavaScript library that detects support for many HTML5 & CSS3 features.

Plus:

Appendix A: The All-In-One Almost-Alphabetical No-Bullshit Guide to Detecting Everything.

For a quick, non-programming check: The HTML5 Test