C++ Exception Handling MCQ Quiz - MCQ questions and answers

Welcome to our blog post, "C++ Exception Handling MCQ Quiz - MCQ Questions and Answers." Exception handling is a crucial aspect of robust C++ programming, ensuring that your applications can gracefully handle and recover from unexpected situations. 

This quiz is designed to test and reinforce your knowledge of exception handling in C++. Whether you're a student, a programming enthusiast, or a professional developer, these carefully crafted multiple-choice questions offer a great way to assess your understanding of C++'s exception-handling mechanisms. Accompanied by detailed answers, this quiz serves as an effective learning tool, helping you to solidify your grasp of this important concept in C++. Let's jump into the world of C++ exception handling and put your skills to the test!

1. What is exception handling in C++?

a) Handling syntax errors in code
b) Dealing with runtime errors in a controlled way
c) Managing memory allocation errors only
d) Handling errors during compile time

Answer:

b) Dealing with runtime errors in a controlled way

Explanation:

Exception handling in C++ involves dealing with runtime errors in a controlled and systematic way using try, catch, and throw statements.

2. Which keyword is used to throw an exception in C++?

a) throw
b) catch
c) try
d) error

Answer:

a) throw

Explanation:

The 'throw' keyword is used to throw an exception when a problem is detected in a program.

3. Which block is used to handle exceptions in C++?

a) try block
b) catch block
c) throw block
d) error block

Answer:

b) catch block

Explanation:

The catch block is used to handle exceptions. It contains code that is executed when an exception is thrown in the corresponding try block.

4. What is the purpose of the try block in C++?

a) To define a block of code to be tested for errors
b) To handle the exception
c) To throw an exception
d) To declare an exception

Answer:

a) To define a block of code to be tested for errors

Explanation:

The try block contains a block of code that might generate an exception and is followed by one or more catch blocks to handle potential exceptions.

5. How many catch blocks can follow a try block?

a) Only one
b) At most two
c) As many as needed
d) None

Answer:

c) As many as needed

Explanation:

A try block can be followed by multiple catch blocks, each designed to handle a different type of exception.

6. Can a catch block exist without a corresponding try block?

a) Yes
b) No
c) Only in specific cases
d) Only if it does not throw any exception

Answer:

b) No

Explanation:

A catch block must always be associated with a try block. It cannot exist independently in a C++ program.

7. What happens if an exception is not caught?

a) It is ignored
b) The program continues execution
c) It causes a runtime error
d) The program terminates abnormally

Answer:

d) The program terminates abnormally

Explanation:

If an exception is thrown but not caught, it leads to abnormal termination of the program.

8. Can you have an empty throw statement in C++?

a) Yes, it rethrows the current exception
b) No, it's not allowed
c) Yes, but it throws a new exception
d) Only inside a catch block

Answer:

a) Yes, it rethrows the current exception

Explanation:

An empty throw statement, used inside a catch block, is used to rethrow the currently handled exception. It is useful for catching an exception, performing some cleanup, and then rethrowing it.

9. What is the correct syntax for catching any type of exception in C++?

a) catch(...)
b) catch(exception)
c) catch(all)
d) catch(any)

Answer:

a) catch(...)

Explanation:

The catch(...) syntax is used to catch any type of exception. It's known as a catch-all handler.

10. What does the 'std::exception' class represent in C++?

a) A specific type of error
b) The base class for all standard exception classes
c) Only runtime errors
d) Only logic errors

Answer:

b) The base class for all standard exception classes

Explanation:

'std::exception' is the base class for all standard exception classes in C++. It provides a common base to derive custom exceptions.

11. Can a function signature include an exception specification in C++?

a) Yes
b) No
c) Only for certain functions
d) Only in C++11 and newer

Answer:

a) Yes

Explanation:

In C++, a function signature can include an exception specification, which lists the exceptions that the function might throw. However, this practice is generally discouraged in modern C++.

12. How do you create a custom exception in C++?

a) By using the error keyword
b) By inheriting from the std::exception class
c) By defining a new namespace
d) By using the throw keyword

Answer:

b) By inheriting from the std::exception class

Explanation:

Custom exceptions in C++ can be created by inheriting from the std::exception class and overriding the what() method to provide a custom error message.

13. What is exception propagation in C++?

a) Throwing an exception from a nested block
b) Catching all exceptions in a single block
c) Spreading exceptions to different classes
d) Throwing an exception from a function to its caller

Answer:

d) Throwing an exception from a function to its caller

Explanation:

Exception propagation refers to the process where an exception is thrown from a function and is caught in the caller of that function.

14. What is the output of the following C++ code if an exception is not thrown?

   try {
       // Code that does not throw an exception
   } catch(...) {
       cout << "Exception caught";
   }
a) "Exception caught"
b) No output
c) Error
d) Undefined behavior

Answer:

b) No output

Explanation:

If no exception is thrown in the try block, the catch block is not executed, and there will be no output.

15. What type of exceptions does the 'std::runtime_error' class represent?

a) Compile-time errors
b) Logic errors
c) Errors that occur during program execution
d) Memory allocation errors

Answer:

c) Errors that occur during program execution

Explanation:

The std::runtime_error class in C++ is used to represent exceptions that occur during the execution of the program, such as arithmetic errors or invalid arguments.

16. Can multiple exceptions be thrown from a single try block?

a) Yes, multiple exceptions can be thrown
b) No, only one exception can be thrown
c) Yes, but they must be of the same type
d) No, it's not allowed in C++

Answer:

b) No, only one exception can be thrown

Explanation:

Only one exception can be thrown from a try block at a time. Once an exception is thrown, control is transferred to the catch block, and the rest of the try block is skipped.

17. What is a nested try block in C++?

a) A try block within another try block
b) A try block that catches its own exceptions
c) A try block followed by multiple catch blocks
d) A syntax error

Answer:

a) A try block within another try block

Explanation:

Nested try blocks refer to a try block placed inside another try block. This is useful for handling exceptions in different scopes or for different parts of code within a function.

18. What happens when an exception is thrown and caught in the same function?

a) The function resumes execution after the catch block
b) The function immediately returns
c) The program terminates
d) The exception is rethrown automatically

Answer:

a) The function resumes execution after the catch block

Explanation:

When an exception is thrown and caught in the same function, the function continues execution after the catch block, unless the catch block contains a return statement or rethrows the exception.

19. How do you declare that a function might throw a specific exception in C++?

a) By using the throw keyword in the function declaration
b) By listing the exception type in the function parameters
c) By documenting the exceptions in comments
d) It is not possible to declare specific exceptions

Answer:

a) By using the throw keyword in the function declaration

Explanation:

In C++, a function can declare that it might throw specific exceptions using the throw keyword followed by the exception type in the function declaration. However, this is considered deprecated in modern C++ standards.

20. Is it possible to catch an exception thrown by a constructor in C++?

a) Yes, by surrounding the object creation with a try-catch block
b) No, it's not possible to catch exceptions from constructors
c) Only if the constructor is default
d) Only in C++11 and newer

Answer:

a) Yes, by surrounding the object creation with a try-catch block

Explanation:

Exceptions thrown by constructors can be caught in C++ by placing the object creation code inside a try block and catching the exception in the corresponding catch block.

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