When to use pass by value, pass by reference, void data types with functions

Purpose	Function Type	Parameters	To Return Result
To compute or obtain as input a single numeric or character value	Same as type of value to be computed or input.	Input parameters hold copies of data provided by calling function.	Function code includes a return statement with an expression whose value is the result.
To produce printed output containing values of numeric or character arguments.	void	Input parameters hold copies of data provided by calling function.	No result is returned.
To compute multiple numeric or character results	void	Input parameters hold copies of data provided by calling function. Output parameters are pointers to actual arguments	Results are stored in the calling function’s data area by indirect assignment through output parameters(pointers). There is no return statement.
To modify argument values	void	Input/output parameters are pointers to actual arguments. Input data is accessed by indirect reference through parameters.	Results are stored in the calling function’s data area by indirect assignment through output parameters. There is no return statement.