The following example shows how a programmer might avoid a division by zero error by explicitly checking for the error condition:if(gallonsOfGas != 0)mpg = milesDriven /gallonsOfGas;else mpg = 0;Another possible way to deal with this is to use exception handling mechanisms. What factors help the programmer decide which of these methods to use?

Question

What will be an ideal response?

Answer 1

The example code represents the most efficient method of handling the error if you think it will be a frequent problem. Because a program that contains this code does not have to instantiate an Exception object every time the user enters a 0 for the value of gallonsOfGas, the program saves time and computer memory. On the other hand, if you think dividing by zero will be infrequent, then the decision will execute many times when it is not needed. In other words, if a user enters 0 for gallonsOfGas in only one case out of 1,000, then the if statement is executed unnecessarily 999 times. In that case, it is more efficient to eliminate the if test and instantiate an Exception object when needed.
Another advantage to using exception handling instead of decision making to control errors is that when a program's main logic is interrupted by a series of statements and decisions that might detect errors, the program can become more complicated and difficult to understand. The object-oriented approach to error handling separates a program's main tasks from code that deals with rare exceptions.