Function Handling
- call_user_func - Call the callback given by the first parameter
- call_user_func_array - Call a callback with an array of parameters
- create_function - Create a function dynamically by evaluating a string of code
- forward_static_call - Call a static method
- forward_static_call_array - Call a static method and pass the arguments as array
- 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