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Last updated: Tue, 19 Sep 2006


(PHP 3, PHP 4, PHP 5)

define -- Defines a named constant


bool define ( string name, mixed value [, bool case_insensitive] )

Defines a named constant at runtime. See the section on constants for more details.

The name of the constant is given by name; the value is given by value.

The optional third parameter case_insensitive is also available. If the value TRUE is given, then the constant will be defined case-insensitive. The default behaviour is case-sensitive; i.e. CONSTANT and Constant represent different values.

Example 1. Defining Constants

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."


Returns TRUE on success or FALSE on failure.

See also defined(), constant() and the section on Constants.

Last updated: Tue, 19 Sep 2006