An example where a function pointer parameter is used to define the function’s own behavior can be found in the C standard library’s Quick Sort function, qsort(), which takes a compare ...

An aggregate function includes values grouped together to form a single value that provides a summary of the data list.

The advantage here is a more straightforward virtual call and a nicer syntax resembling C++ because the virtual draw () function, for example, can be invoked using the dot operator, like rect.draw ...