define
define
(PHP 4, PHP 5, PHP 7)
define — Defines a named constant
Description
bool define ( string $name , mixed $value [, bool $case_insensitive = false ] )
Defines a named constant at runtime.
Parameters
-
name
-
The name of the constant.
-
value
-
The value of the constant. In PHP 5,
value
must be a scalar value (integer, float, string, boolean, orNULL
). In PHP 7, array values are also accepted.WarningWhile it is possible to define resource constants, it is not recommended and may cause unpredictable behavior.
-
case_insensitive
-
If set to
TRUE
, the constant will be defined case-insensitive. The default behavior is case-sensitive; i.e. CONSTANT and Constant represent different values.Note:
Case-insensitive constants are stored as lower-case.
Return Values
Returns TRUE
on success or FALSE
on failure.
Changelog
Version | Description |
---|---|
7.0.0 | array values are allowed. |
Examples
Example #1 Defining Constants
<?php define("CONSTANT", "Hello world."); echo CONSTANT; // outputs "Hello world." echo Constant; // outputs "Constant" and issues a notice. define("GREETING", "Hello you.", true); echo GREETING; // outputs "Hello you." echo Greeting; // outputs "Hello you." // Works as of PHP 7 define('ANIMALS', array( 'dog', 'cat', 'bird' )); echo ANIMALS[1]; // outputs "cat" ?>
See Also
- defined() - Checks whether a given named constant exists
- constant() - Returns the value of a constant
- The section on Constants
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Licensed under the Creative Commons Attribution License v3.0 or later.
https://secure.php.net/manual/en/function.define.php