JavaScript Detecting browser
Introduction
Browsers, as they have evolved, offered more features to Javascript. But often these features are not available in all browsers. Sometimes they may be available in one browser, but yet to be released on other browsers. Other times, these features are implemented differently by different browsers. Browser detection becomes important to ensure that the application you develop runs smoothly across different browsers and devices.
Remarks
Use feature detection when possible.
There are some reasons to use browser detection (e.g. Giving a user directions on how to install a browser plugin or clear their cache), but generally feature detection is considered best practice. If you are using browser detection be sure that it is absolutely nesesary.
Modernizr is a popular, lightweight JavaScript library that makes feature detection easy.
