C++ How to Program, 10/e

17.2.4 Defining a catch Handler to Process a DivideByZeroException

You saw in Section 7.10 that exceptions are processed by catch handlers. At least one catch handler (lines 34–37) must immediately follow each try block. An exception parameter should always be declared as a reference to the type of exception the catch handler can process (DivideByZeroException in this case)—this prevents copying the exception object when it’s caught and allows a catch handler to properly catch derived-class exceptions as well.

When an exception occurs in a try block, the catch handler that executes is the first one whose type matches the type of the exception that occurred (i.e., the type in the catch block matches the thrown exception type exactly or is a ...