Variables are used to make processes we script out more dynamic. In the
programming world the word variable means
"a symbolic name associated with a value and whose associated value may be changed".
PHP sports a cool feature called automatic data typing. A PHP developer can claim variables and use them in most common situations without having to claim the data type that the variable is.
How to create variable
Predefined Variables
There are a set of predefined variables in PHP that are always available for use in any script or scope in your applications. When data is created, sent, or stored using mechanisms that create superglobal variables, we can then access those variables site-wide or all throughout our scripts and scope. Predefined superglobals are available to all of your scripts that are part of a website or application you are creating.
The superglobal variables are:
example
Magic Constants (Predefined)
"a symbolic name associated with a value and whose associated value may be changed".
PHP sports a cool feature called automatic data typing. A PHP developer can claim variables and use them in most common situations without having to claim the data type that the variable is.
How to create variable
- PHP variables must made by placing a dollar sign [ $ ] and then the name of the variable directly after it.
- Variable name must starts from character or underscore.
- Do not use a NUMBER to start a variable name.
Predefined Variables
There are a set of predefined variables in PHP that are always available for use in any script or scope in your applications. When data is created, sent, or stored using mechanisms that create superglobal variables, we can then access those variables site-wide or all throughout our scripts and scope. Predefined superglobals are available to all of your scripts that are part of a website or application you are creating.
The superglobal variables are:
| $_GET | Stores any variables created using the GET method |
| $_POST | Stores any variables created using the POST method |
| $_REQUEST | Stores any variables created through a user input script (it can access both POST or GET) |
| $_FILES | Stores any file upload variables created through user input scripts |
| $_SESSION | Stores any variables created through registering session variables |
| $_COOKIE | Stores any variables created through setcookie |
| $GLOBALS | Stores any variables that have been globally defined |
| $_SERVER | Stores server information such as headers, file names, reference paths, and current page. |
| $_ENV | Stores any variables associated with the server environment. |
example
Magic Constants (Predefined)
