When you write programs with multiple functions, they must have some way to communicate with each other. They need to be able to pass information back and forth. By information, I mean data - variables, constants, and expressions. There are several different mechanisms in C++ to do this:

1. global data
2. value parameters
3. reference parameters
4. return statement

Given specific situations, some mechanisms may be more appropriate than others; some mechanisms may be inappropriate.

This set of exercises will explore these various mechanisms. Each exercise involves running two different versions of a simple payroll program. In each case, the payroll program consists of 2 functions: main() and CalcPay().

Function Tasks

The following diagram illustrates the data that must be communicated between the two functions.

Exercise 1 - Global Data vs Local Data

Exercise 2 - Value Parameters vs Reference Parameters

Exercise 3 - Void Functions vs Value-returning Functions