Java By Comparison

There are two ways to write error-free programs; only the third works.

Alan J. Perlis

Chapter 5Prepare for Things Going Wrong

Do you own a car? Do you have insurance for it? If not, you’d better get a policy now. It can cost you a lot of money, and chances are, you’ll drive your car for thousands of miles without any trouble. But it just takes a moment of bad luck to leave you with life-changing consequences. That’s why you need insurance to act as a safety net for your really expensive things (cars, houses) and your really important things (your health!).

It’s similar with code. Most of the time, your program will execute just fine and take the happy path (the default control-flow path without any exceptional or erroneous conditions). But ...