XXIX. Function Handling functions

These functions all handle various operations involved in working with functions.

Table of Contents
call_user_func_array --  Call a user function given with an array of parameters
call_user_func --  Call a user function given by the first parameter
create_function -- Create an anonymous (lambda-style) function
func_get_arg -- Return an item from the argument list
func_get_args --  Returns an array comprising a function's argument list
func_num_args --  Returns the number of arguments passed to the function
function_exists --  Return TRUE if the given function has been defined
get_defined_functions --  Returns an array of all defined functions
register_shutdown_function --  Register a function for execution on shutdown
register_tick_function --  Register a function for execution on each tick
unregister_tick_function --  De-register a function for execution on each tick