Question 1

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

Accepted Answer

The "throw()" specification after the argument list indicates that the function does not throw any exceptions. Therefore, the statement "should throw no exception of any type" is true.

Question 2

Compilers will check code in functions against exception specifications.

Accepted Answer

Compilers may enforce exception specifications in some languages (like C++ until C++17), but in general, they check code for syntax and semantic errors rather than against specific exception specifications. Exception handling is more about runtime behavior than compile-time checks.

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.

Accepted Answer

Since the function uses an exception specification that includes only int, it means that any other type of exception, including double, will not be caught by the catch block. Therefore, the program will terminate with an unhandled exception.

Question 4

The default action of unexpected()can be changed.

Accepted Answer

The default action of unexpected() in Python can be changed by defining a custom exception class and attaching it as an attribute to the current module or class. This way, when the unexpected() function is called, it will raise the custom exception instead of the standard SystemExit exception.

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.

Accepted Answer

When an exception is thrown, it transfers control to a calling program unit that can manage the event or terminates the program.

Question 6

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

Accepted Answer

In C++, an exception is signaled or raised with the keyword `throw` followed by an exception object, not `catch`. The `catch` keyword is used to define a block of code that handles the exception.

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.

Accepted Answer

This is true. If a base class B is mentioned in an exception specification, it includes all derived classes of B, such as D, in the same exception specification. Therefore, if an exception is thrown from an object of class D, it will also be caught by the exception handling mechanism for class B.

Question 8

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

Accepted Answer

Exceptions can be thrown for non-error situations such as resource allocation failures or invalid input from external sources. However, exceptions should not be used as a substitute for normal program flow or simple error checking.

Question 9

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

Accepted Answer

The exception specification only affects the exceptions that can be thrown by the function, not the exceptions that are caught within the function. Therefore, if an exception is thrown and caught within the function, it does not matter whether it is listed in the exception specification or not.

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().

Accepted Answer

When an exception is thrown in a function and not handled there, it is propagated to the calling function. This continues until the exception is either caught by a try-catch block or the program terminates. This is known as exception propagation or propagation of exceptions.

Question 11

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

Accepted Answer

In C++, an exception object does not need to be derived from the exception class defined in the standard library; any type (primitive, object, etc.) can be thrown as an exception.

Question 12

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

Accepted Answer

In C++, an exception object can be a user-defined type or any type that is built-into C++ language, such as int, char, float, etc.

Question 13

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

Accepted Answer

The answer of Statements that cause an exception must be...

Question 14

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

Accepted Answer

If a function does not have an exception specification, it means that it can throw any type of exception; exceptions are not prohibited.

Question 15

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

Accepted Answer

The try block is where code is executed that could potentially throw an exception. If an exception is thrown, it is detected in the try block and control is passed to the corresponding catch block(s).

Question 16

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

Accepted Answer

The context in which an exception is handled (or managed) is the catch block, not the throw block. The throw block is where the exception is thrown or raised.

Question 17

An uncaught exception in C++ is ignored.

Accepted Answer

An uncaught exception in C++ terminates the program by calling `std::terminate()` function, which may not necessarily ignore the exception.

Question 18

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

Accepted Answer

When an exception is thrown and caught, the program can continue to run the rest of the code outside the try-catch block.

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.

Accepted Answer

The answer of Suppose an exception of type E is...

Question 20

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

Accepted Answer

Only catch blocks with exact matching types or subtypes will be selected in type matching.

Quiz 18: Exception Handling