- PHP Tutorial
- PHP - Home
- PHP - Introduction
- PHP - Environment Setup
- PHP - History
- PHP - Syntax
- PHP - Hello World
- PHP - Comments
- PHP - Variables
- PHP - Echo/Print
- PHP - var_dump
- PHP - $ and $$ Variables
- PHP - Constants
- PHP - Magic Constants
- PHP - Data Types
- PHP - Type Casting
- PHP - Type Juggling
- PHP - Strings
- PHP - Boolean
- PHP - Integers
- PHP - Files & I/O
- PHP - Heredoc & Nowdoc
- PHP - Compound Types
- PHP - File Include
- PHP - Date & Time
- PHP - Scalar Type Declarations
- PHP - Return Type Declarations
- PHP Operators
- PHP - Operators
- PHP - Arithmatic Operators
- PHP - Comparison Operators
- PHP - Logical Operators
- PHP - Assignment Operators
- PHP - String Operators
- PHP - Array Operators
- PHP - Conditional Operators
- PHP - Spread Operator
- PHP - Null Coalescing Operator
- PHP - Spaceship Operator
- PHP Control Statements
- PHP - Decision Making
- PHP - If…Else Statement
- PHP - Switch Statement
- PHP - For Loop
- PHP - Foreach Loop
- PHP - While Loop
- PHP - Do…While Loop
- PHP - Break Statement
- PHP - Continue Statement
- PHP Arrays
- PHP - Arrays
- PHP - Indexed Array
- PHP - Associative Array
- PHP - Multidimensional Array
- PHP - Array Functions
- PHP - Constant Arrays
- PHP Functions
- PHP - Functions
- PHP - Function Parameters
- PHP - Call by value
- PHP - Call by Reference
- PHP - Default Arguments
- PHP - Named Arguments
- PHP - Variable Arguments
- PHP - Returning Values
- PHP - Passing Functions
- PHP - Recursive Functions
- PHP - Type Hints
- PHP - Variable Scope
- PHP - Strict Typing
- PHP - Anonymous Functions
- PHP - Arrow Functions
- PHP - Variable Functions
- PHP - Global Variables
- PHP Superglobals
- PHP - Superglobals
- PHP - $GLOBALS
- PHP - $_SERVER
- PHP - $_REQUEST
- PHP - $_POST
- PHP - $_GET
- PHP - $_FILES
- PHP - $_ENV
- PHP - $_COOKIE
- PHP - $_SESSION
- PHP File Handling
- PHP - File Handling
- PHP - Open File
- PHP - Read File
- PHP - Write File
- PHP - File Existence
- PHP - Download File
- PHP - Copy File
- PHP - Append File
- PHP - Delete File
- PHP - Handle CSV File
- PHP - File Permissions
- PHP - Create Directory
- PHP - Listing Files
- Object Oriented PHP
- PHP - Object Oriented Programming
- PHP - Classes and Objects
- PHP - Constructor and Destructor
- PHP - Access Modifiers
- PHP - Inheritance
- PHP - Class Constants
- PHP - Abstract Classes
- PHP - Interfaces
- PHP - Traits
- PHP - Static Methods
- PHP - Static Properties
- PHP - Namespaces
- PHP - Object Iteration
- PHP - Encapsulation
- PHP - Final Keyword
- PHP - Overloading
- PHP - Cloning Objects
- PHP - Anonymous Classes
- PHP Web Development
- PHP - Web Concepts
- PHP - Form Handling
- PHP - Form Validation
- PHP - Form Email/URL
- PHP - Complete Form
- PHP - File Inclusion
- PHP - GET & POST
- PHP - File Uploading
- PHP - Cookies
- PHP - Sessions
- PHP - Session Options
- PHP - Sending Emails
- PHP - Post-Redirect-Get (PRG)
- PHP - Flash Messages
- PHP AJAX
- PHP - AJAX Introduction
- PHP - AJAX Search
- PHP - AJAX XML Parser
- PHP - AJAX Auto Complete Search
- PHP - AJAX RSS Feed Example
- PHP XML
- PHP - XML Introduction
- PHP - Simple XML Parser
- PHP - SAX Parser Example
- PHP - DOM Parser Example
- PHP Login Example
- PHP - Login Example
- PHP - Facebook Login
- PHP - Paypal Integration
- PHP - MySQL Login
- PHP Advanced
- PHP - MySQL
- PHP.INI File Configuration
- PHP - Array Destructuring
- PHP - Coding Standard
- PHP - Regular Expression
- PHP - Error Handling
- PHP - Try…Catch
- PHP - Bugs Debugging
- PHP - For C Developers
- PHP - For PERL Developers
- PHP - Frameworks
- PHP - Core PHP vs Frame Works
- PHP - Design Patterns
- PHP - Closure::call()
- PHP - Filtered unserialize()
- PHP - IntlChar
- PHP - CSPRNG
- PHP - Expectations
- PHP - Use Statement
- PHP - Integer Division
- PHP - Deprecated Features
- PHP - Removed Extensions & SAPIs
- PHP - Built-In Functions
- PHP Useful Resources
- PHP - Questions & Answers
- PHP - Useful Resources
- PHP - Discussion
PHP - Predefined Variables
PHP provides a large number of predefined variables to any script which it runs. PHP provides an additional set of predefined arrays containing variables from the web server the environment, and user input. These new arrays are called superglobals −
All the following variables are automatically available in every scope.
PHP Superglobals
Sr.No | Variable & Description |
---|---|
1 | $GLOBALS Contains a reference to every variable which is currently available within the global scope of the script. The keys of this array are the names of the global variables. |
2 |
$_SERVER This is an array containing information such as headers, paths, and script locations. The entries in this array are created by the web server. There is no guarantee that every web server will provide any of these. See next section for a complete list of all the SERVER variables. |
3 |
$_GET An associative array of variables passed to the current script via the HTTP GET method. |
4 |
$_POST An associative array of variables passed to the current script via the HTTP POST method. |
5 | $_FILES An associative array of items uploaded to the current script via the HTTP POST method. |
6 |
$_REQUEST An associative array consisting of the contents of $_GET, $_POST, and $_COOKIE. |
7 | $_COOKIE An associative array of variables passed to the current script via HTTP cookies. |
8 |
$_SESSION An associative array containing session variables available to the current script. |
9 |
$_PHP_SELF A string containing PHP script file name in which it is called. |
10 |
$php_errormsg $php_errormsg is a variable containing the text of the last error message generated by PHP. |
Server variables: $_SERVER
$_SERVER is an array containing information such as headers, paths, and script locations. The entries in this array are created by the web server. There is no guarantee that every web server will provide any of these.
Sr.No | Variable & Description |
---|---|
1 | $_SERVER['PHP_SELF'] The filename of the currently executing script, relative to the document root |
2 |
$_SERVER['argv'] Array of arguments passed to the script. When the script is run on the command line, this gives C-style access to the command line parameters. When called via the GET method, this will contain the query string. |
3 |
$_SERVER['argc'] Contains the number of command line parameters passed to the script if run on the command line. |
4 |
$_SERVER['GATEWAY_INTERFACE'] What revision of the CGI specification the server is using; i.e. 'CGI/1.1'. |
5 |
$_SERVER['SERVER_ADDR'] The IP address of the server under which the current script is executing. |
6 |
$_SERVER['SERVER_NAME'] The name of the server host under which the current script is executing. If the script is running on a virtual host, this will be the value defined for that virtual host. |
7 |
$_SERVER['SERVER_SOFTWARE'] Server identification string, given in the headers when responding to requests. |
8 | $_SERVER['SERVER_PROTOCOL'] Name and revision of the information protocol via which the page was requested; i.e. 'HTTP/1.0'; |
9 | $_SERVER['REQUEST_METHOD'] Which request method was used to access the page; i.e. 'GET', 'HEAD', 'POST', 'PUT'. |
10 |
$_SERVER['REQUEST_TIME'] The timestamp of the start of the request. Available since PHP 5.1.0. |
11 |
$_SERVER['QUERY_STRING'] The query string, if any, via which the page was accessed. |
12 |
$_SERVER['DOCUMENT_ROOT'] The document root directory under which the current script is executing, as defined in the server's configuration file. |
13 |
$_SERVER['HTTP_ACCEPT'] Contents of the Accept: header from the current request, if there is one. |
14 | $_SERVER['HTTP_ACCEPT_CHARSET'] Contents of the Accept-Charset: header from the current request, if there is one. Example: 'iso-8859-1,*,utf-8'. |
15 |
$_SERVER['HTTP_ACCEPT_ENCODING'] Contents of the Accept-Encoding: header from the current request, if there is one. Example: 'gzip'. |
16 |
$_SERVER['HTTP_ACCEPT_LANGUAGE'] Contents of the Accept-Language: header from the current request, if there is one. Example: 'en'. |
17 |
$_SERVER['HTTP_CONNECTION'] Contents of the Connection: header from the current request, if there is one. Example: 'Keep-Alive'. |
18 |
$_SERVER['HTTP_HOST'] Contents of the Host: header from the current request, if there is one. |
19 | $_SERVER['HTTP_REFERER'] The address of the page (if any) which referred the user agent to the current page. |
20 |
$_SERVER['HTTP_USER_AGENT'] This is a string denoting the user agent being which is accessing the page. A typical example is: Mozilla/4.5 [en] (X11; U; Linux 2.2.9 i586). |
21 |
$_SERVER['HTTPS'] Set to a non-empty value if the script was queried through the HTTPS protocol. |
22 |
$_SERVER['REMOTE_ADDR'] The IP address from which the user is viewing the current page. |
23 |
$_SERVER['REMOTE_HOST'] The Host name from which the user is viewing the current page. The reverse dns lookup is based off the REMOTE_ADDR of the user. |
24 |
$_SERVER['REMOTE_PORT'] The port being used on the user's machine to communicate with the web server. |
25 |
$_SERVER['SCRIPT_FILENAME'] The absolute pathname of the currently executing script. |
26 | $_SERVER['SERVER_ADMIN'] The value given to the SERVER_ADMIN (for Apache) directive in the web server configuration file. |
27 |
$_SERVER['SERVER_PORT'] The port on the server machine being used by the web server for communication. For default setups, this will be '80'. |
28 |
$_SERVER['SERVER_SIGNATURE'] String containing the server version and virtual host name which are added to server-generated pages, if enabled. |
29 |
$_SERVER['PATH_TRANSLATED'] Filesystem based path to the current script. |
30 |
$_SERVER['SCRIPT_NAME'] Contains the current script's path. This is useful for pages which need to point to themselves. |
31 | $_SERVER['REQUEST_URI'] The URI which was given in order to access this page; for instance, '/index.html'. |
32 |
$_SERVER['PHP_AUTH_DIGEST'] When running under Apache as module doing Digest HTTP authentication this variable is set to the 'Authorization' header sent by the client. |
33 |
$_SERVER['PHP_AUTH_USER'] When running under Apache or IIS (ISAPI on PHP 5) as module doing HTTP authentication this variable is set to the username provided by the user. |
34 |
$_SERVER['PHP_AUTH_PW'] When running under Apache or IIS (ISAPI on PHP 5) as module doing HTTP authentication this variable is set to the password provided by the user. |
35 | $_SERVER['AUTH_TYPE'] When running under Apache as module doing HTTP authenticated this variable is set to the authentication type. |