We can distinguish 3 categories: checked exceptions-Problems to do with the program's interaction with“the world”. unchecked exceptions- The world is unpredictable,so we elf (i.e.violations of the contra would expect these things to system errors-Problems happen in prod tion code,and so neer These are outside our contror. These should be removed by testing,and not occur in production code. The World Checked Exceptions Unchecked Program Exceptions System System Errors 88 We can distinguish 3 categories: • checked exceptions — Problems to do with the program's interaction with “the world”. • unchecked exceptions — Problems within the program itself (i.e. violations of the contract, or bugs). • system errors — Problems with the underlying system. These are outside our control.The world is unpredictable, so we would expect these things to happen in production code, and so need to handle them. These should be removed by testing, and not occur in production code. Unchecked Exceptions System Errors Program System The World Checked Exceptions