C++: A Dialog Programming with the C++ Standard Library

Changing the Course of Execution

In our examples so far, the program always executes the same statements in the same order. However, any real program is going to need to alter its behavior according to the data it is processing. For example, in a banking application, it might be necessary to send out a notice to a depositor whenever the balance in a particular account drops below a certain level; or perhaps the depositor would just be charged some exorbitant fee in that case. Either way, the program has to do something different depending on the balance. In particular, let's suppose that the “Absconders and Defaulters National Bank” has a minimum balance requirement of $10,000.^[37] Furthermore, let's assume that if you have less than that amount ...