Deck 18: Exception Handling

Question 1

A function declared thus: void func(argument_list)throw();should throw no exception of any type.

Answer 1

True

Question 2

Compilers will check code in functions against exception specifications.

Answer 2

False

Question 3

A function uses an exception specification that includes only int,but an exception of type double is thrown.A catch block is provided that catches a double,so things proceed properly.

Answer 3

False

Question 4

The default action of unexpected()can be changed.

Question 5

When an event occurs that cannot be managed locally,an exception may be thrown.Throwing the exception object transfers control and information gleaned locally to some calling program unit that manages the event,or the program terminates.

Question 6

An exception is signaled or raised with the keyword catch followed by an exception object that may be of any C++ type.

Question 7

Mentioning a base class B in an exception specification includes a class D objects,where D is derived from B,in the exception specification.

Question 8

A circumstance in C++ where an exception is thrown must be an error.

Question 9

The exception specification for a function has no effect on an exception that is caught within the function.

Question 10

If an exception is thrown in a function,say,f(),but not handled there,the exception is propagated to the function that called f().

Question 11

In C++ an exception object must be derived from the exception class defined in the standard library.

Question 12

In C++,an exception object can be a user-defined type or any type that is built-into C++ language.

Question 13

Statements that cause an exception must be part of a try block.

Question 14

A function does not have an exception specification at all,so exceptions are prohibited.

Question 15

The context in which the throwing of an exception is detected is the try block.

Question 16

The context in which an exception is handled (or managed)is the throw block.

Question 17

An uncaught exception in C++ is ignored.

Question 18

A program can continue to run after an exception has been thrown and caught.

Question 19

Suppose an exception of type E is thrown in a function but not listed in the exception specification,and is not caught in the function.The exception will be caught in a calling function that has a catch block that declares an exception of that type.

Question 20

In type matching to select a catch block,only exact matches work.

Question 21

Describe the circumstances that the unexpected()function will be called.

Question 22

How can you write a catch block that will catch all exceptions that have been thrown but not yet caught?

Question 23

Write a definition for an exception class,E,that contains an error number and a string type error name.Include a constructor that creates an E object and initializes both members.Provide accessors for both the message and error number.

Question 24

What is the purpose of exception handling?

Question 25

The situations where exceptions are used put the try block with the throw statement followed by the catch block all in one function.

Question 26

Explain how the mechanism for deciding which catch block catches an exception is like the mechanism for deciding which function definition is used when an overloaded function is called.

Question 27

A function that satisfies its preconditions but cannot fulfill its postconditions should throw an exception.

Question 28

Write just a catch block with a catch block parameter type that will catch all exceptions that are yet uncaught.

Question 29

When an exception is thrown,the function finishes its execution,its value is returned,then control is transferred to the catch block.