Essential C++

2.3. Providing Default Parameter Values

Printing a trace of our bubble sort program to ofil required that I make ofil available to the multiple functions I wished to debug. Because I was responding to unexpected and unwelcomed behavior, I chose the quickest solution to the problem of making an object visible across multiple functions: I defined ofil at file scope.

As a general programming rule, however, it is better to communicate between functions using parameters rather than use objects defined at file scope. One reason is that a function that is dependent on an object defined at file scope is harder to reuse in a different context. The function is also harder to modify: We must understand not only the logic specific to the function but also ...