defined(3) [php man page]

DEFINED(3)								 1								DEFINED(3)

defined - Checks whether a given named constant exists

SYNOPSIS

       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)

METHOD_EXISTS(3)							 1							  METHOD_EXISTS(3)

method_exists - Checks if the class method exists

SYNOPSIS

       bool method_exists (mixed  $object, string  $method_name)

DESCRIPTION

	Checks if the class method exists in the given $object.

PARAMETERS

	      o $object
		- An object instance or a class name

	      o $method_name
		- The method name

RETURN VALUES

	Returns TRUE if the method given by $method_name has been defined for the given $object, FALSE otherwise.

NOTES

       Note

	      Using this function will use any registered autoloaders if the class is not already known.

EXAMPLES

       Example #1

	      method_exists(3) example

	      <?php
	      $directory = new Directory('.');
	      var_dump(method_exists($directory,'read'));
	      ?>

	      The above example will output:

	      bool(true)

       Example #2

	      Static method_exists(3) example

	      <?php
	      var_dump(method_exists('Directory','read'));
	      ?>

	      The above example will output:

	      bool(true)

SEE ALSO

       function_exists(3), is_callable(3), class_exists(3).

PHP Documentation Group 													  METHOD_EXISTS(3)