Introduction
In addition to user defined variables, PHP populates the global namespace with a number of predefined variables called superglobals. They are always available to be accessed from within any function or method, without specifying the global keyword. List of supperglobals is given below −
$GLOBALS | References all variables available in global scope |
$_?SERVER | Server and execution environment information |
$_?GET | HTTP GET variables |
$_?POST | HTTP POST variables |
$_?FILES | HTTP File Upload variables |
$_?REQUEST | HTTP Request variables |
$_?SESSION | Session variables |
$_?ENV | Environment variables |
$_?COOKIE | HTTP Cookies |
$php_?errormsg | The previous error message |
$HTTP_?RAW_?POST_?DATA | Raw POST data |
$http_?response_?header | HTTP response headers |
$argc | The number of arguments passed to script |
$argv | Array of arguments passed to script |