Predefined Variables

PHP provides predefined variables that represent external variables, built-in environment variables, and other information about the execution environment, such as the number and values of the arguments passed to the script in the CLI environment.

Table of Contents

  • Superglobals — Built-in variables that are always available in all scopes
  • $GLOBALS — References all variables available in global scope
  • $_SERVER — Server and execution environment information
  • $_GET — Query string variables
  • $_POST — Form data from HTTP POST requests
  • $_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_response_header — HTTP response headers
  • $argc — The number of arguments passed to script
  • $argv — Array of arguments passed to script