Exceptions: When Things Go Wrong

10.2 Handling Exceptional Conditions

To introduce you to handling exceptional conditions, Figure 10.1 shows a method that computes the average of the first N integers, an admittedly contrived example. We use it mainly to illustrate the basic concepts involved in exception handling. As its precondition suggests, the avgFirstN() method expects that N will be greater than 0. If N happens to be 0, an error will occur in the expression sum/N, because you cannot divide an integer by 0.

Figure 10.1: Poor design. No attempt is made to guard against a divideby-zero error.