SUMMARY
Client detection is one of the most controversial topics in JavaScript. Because of differences in browsers, it is often necessary to fork code based on the browser's capabilities. There are several approaches to client detection, but the following two are used most frequently:
- Capability detection—Tests for specific browser capabilities before using them. For instance, a script may check to see if a function exists before calling it. This approach frees developers from worrying about specific browser types and versions, enabling them to focus on whether the capability exists or not. Capabilities detection cannot accurately detect a specific browser or version.
- User-agent detection—Identifies the browser by looking at its user-agent string. The user-agent string contains a great deal of information about the browser, often including the browser, platform, operating system, and browser version. There is a long history to the development of the user-agent string...
