C++ Primer Plus

A Function Pointer Example

Listing 7.18 demonstrates using function pointers in a program. It calls the estimate() function twice, once passing the betsy() function address and once passing the pam() function address. In the first case, estimate() uses betsy() to calculate the number of hours necessary, and in the second case, estimate() uses pam() for the calculation. This design facilitates future program development. When Ralph develops his own algorithm for estimating time, he doesn’t have to rewrite estimate(). Instead, he merely needs to supply his own ralph() function, making sure it has the correct signature and return type. Of course, rewriting estimate() isn’t a difficult task, but the same principle applies to more complex code. Also ...