Stu Cox explains that there are a ton of ways you might think you can get a yes-or-no answer on whether a browser supports touch or not:
Width media queries
Touch-related DOM events
Pointer media queries
The normal refrain around t...
If you like playing with new features which might not be available in all browsers, you have surely already tried Modernizr. This library allows to test whether the features you want are available or not. As Modernizr adds some CSS classes on the html ...