Detect Android with PHP, Javascript & .htaccess

Android is a Linux-based operating system, designed primarily for touchscreen mobile devices such as smartphones and tablet computers. Andriod is initially developed by Android, Inc. 
While working in web technology environment, many times we came accross the situation where we need to detect that if it is Android is not. This detection can be done in multiple ways like: 
1. Using PHP 
2. Using Javascript 
3. Using .htaccess 
It totally depends on the interest of developer, which mechnaism he/she choose to detect android.

Request Detection for Mobile Application

Market for mobile application is growing with a great speed. Even there are lots of mobile application created in PHP itself. Sometimes, we have common application for web and mobile but need to detect the mobile devices before rendering the content. Here is a useful code snippet to detect the source of request for application using PHP. If application is requested by any mobile device then the function will return true else it will return false.