C++ Primer Plus

The Exception Mechanism

Now let’s see how you can handle problems by using the exception mechanism. A C++ exception is a response to an exceptional circumstance that arises while a program is running, such as an attempt to divide by zero. Exceptions provide a way to transfer control from one part of a program to another. Handling an exception has three components:

• Throwing an exception

• Catching an exception with a handler

• Using a try block

A program throws an exception when a problem shows up. For example, you can modify hmean() in Listing 15.7 to throw an exception instead of call the abort() function. A throw statement, in essence, is a jump; that is, it tells a program to jump to statements at another location. The throw keyword indicates ...