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DEFINED(3)								 1								DEFINED(3)

defined - Checks whether a given named constant exists

bool defined (string $name) DESCRIPTION
Checks whether the given constant exists and is defined. Note If you want to see if a variable exists, use isset(3) as defined(3) only applies to constants. If you want to see if a function exists, use function_exists(3). PARAMETERS
o $name - The constant name. RETURN VALUES
Returns TRUE if the named constant given by $name has been defined, FALSE otherwise. EXAMPLES
Example #1 Checking Constants <?php /* Note the use of quotes, this is important. This example is checking * if the string 'TEST' is the name of a constant named TEST */ if (defined('TEST')) { echo TEST; } ?> SEE ALSO
define(3), constant(3), get_defined_constants(3), function_exists(3), The section on Constants. PHP Documentation Group DEFINED(3)

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