define
Defines a named constant
Syntax
define ( string $name , mixed $value ) : bool
Parameters
name
The name of the constant.
Note: It is possible to define() constants with reserved or even invalid names, whose value can (only) be retrieved with constant(). However, doing so is not recommended.
value
The value of the constant. In PHP 5, value must be a scalar value (integer, float, string, boolean, or NULL). In PHP 7, array values are also accepted.
Warning: While it is possible to define resource constants, it is not recommended and may cause unpredictable behavior.
Return
Returns TRUE on success or FALSE on failure.
Examples
name value | null
<? define("MYCONSTANT", null); var_export(MYCONSTANT); ?>
NULL
name value | boolean
<? define("MYCONSTANT", true); var_export(MYCONSTANT); ?>
true
name value | float
<? define("MYCONSTANT", 0.1); echo MYCONSTANT; ?>
0.1
name value | integer
<? define("MYCONSTANT", 1); echo MYCONSTANT; ?>
1
name value | string
<? define("MYCONSTANT", "Hello World!"); echo MYCONSTANT; ?>
Hello World!
name value | array
<? define("MYCONSTANT", array(0, 1)); print_r(MYCONSTANT); ?>
Array ( [0] => 0 [1] => 1 )
Return
<? $return = define("MYCONSTANT", array(0, 1)); var_export($return); ?>
true