Deck 13: Exception Handling: A Deeper Look

Question 1

All exceptions cause the program to terminate when thrown.

Answer 1

False
many can be resolved if handled properly by the program.

Question 2

After an exception has occurred and a stack trace has been printed,the program may exit or continue executing,depending on the circumstances.

Answer 2

True

Question 3

Which of the following is false regarding the throw point of an exception

A) It specifies the point at which the exception must be handled.
B) It's the initial point at which the exception occurs.
C) It's specified as the top row of the method-call stack at the time the exception occurred.
D) All of the above statements are true.

Answer 3

A

Question 4

In C#,try blocks are used for:

A) testing for infinite loops.
B) testing for exceptions.
C) resolving exceptions.
D) testing code.

Question 5

In many cases,handling an exception allows a program to automatically restart execution of the program from the beginning.

Question 6

Exceptions can occur:

A) from C#'s CLR
B) through explicitly mentioned code in a try block
C) through calls to other methods made in a try block
D) All of the above

Question 7

A FormatException is used to handle:

A) extra spaces input by the user
B) errors with deleting a file from disk
C) wrong data type inputs
D) all of the above

Question 8

When an exception occurs it is said to have been:

A) caught
B) thrown
C) declared
D) handled

Question 9

A catch block that does not specify an exception type or an identifier ____________.

A)is an error
B) cannot catch any exceptions
C) can catch any exceptions
D) None of the above

Question 10

Which of the following statements about try blocks is true

A) The try block must be followed by at least one catch block.
B) The try block must be followed by a finally block.
C) The try block should contain statements that may process an exception.
D) The try block should contain statements that may throw an exception.

Question 11

An exception is:

A) a problem a computer has during construction
B) a problem that a program has during runtime
C) something that the computer does not understand
D) the way a computer signals to the users that it is about to terminate

Question 12

In the catch block below,what is e
Catch (DivideByZeroException

A) The type of the exception being caught
B) The name of catch block's exception parameter
C) A finally block
D) An exception handler
E) {
Console.WriteLine(e);
}

Question 13

In C#,after an exception is handled,control resumes.This is known as the model of exception handling.

A) after the last catch block, termination
B) after the last catch block, resumption
C) just after the throw point, termination
D) just after the throw point, resumption

Question 14

The base class for all exception classes is System.Exception.

Question 15

When an exception occurs,the try block _______.

A) expires

Question 16

Which of the following is not included in an exception's stack trace

A) A descriptive message for the exception.
B) The method-call stack at the time the exception occurred.
C) The name of the exception.
D) Instructions on handling the exception.

Question 17

An uncaught exception:

A) is a possible exception that never actually occurs during the execution of the program.
B) is an exception that occurs for which the matching catch clause is empty.
C) is an exception that occurs for which there are no matching catch clauses.
D) is another term for a thrown exception.

Question 18

What's the difference between a try block and a try statement

A) There is no difference; the terms can be used interchangeably.
B) A try statement refers to the block of code following the keyword try, while the try block refers to the try keyword and the block of code following this keyword.
C) The try block refers to the keyword try followed by a block of code. The try block and its corresponding catch and/or finally clauses together form a try statement.
D) The try statement refers to the keyword try followed by a block of code. The try statement and its corresponding catch and/or finally clauses together form a try block.

Question 19

C# throws an IntegerArithmeticException when division by zero in integer arithmetic occurs.

Question 20

Which of the following statements is false

A) Exception handling enables programmers to write robust and fault-tolerant programs.
B) Exception handling can catch the exception but cannot resolve the exception.
C) Exception handling can resolve exceptions.
D) There are many ways of handling exceptions.

Question 21

There must be a catch clause for every expected exception type.

Question 22

Which of the following statements is false

A) A finally block, if there is one, is placed after the last catch block.
B) A finally block should release all resources acquired in the corresponding try block.
C) The finally block and try block can appear in any order.
D) A finally block is optional.

Question 23

After the last catch block,the required finally block provides code that always executes regardless of whether or not an exception occurs.

Question 24

If an exception is thrown in a catch handler,any code in the handler that follows the thrown exception will:

A) generate a syntax error
B) generate a logic error
C) never be executed
D) run after the finally block is done

Question 25

User-created exceptions can be created by:

A) overriding the Error class.
B) overriding the Exception property.
C) extending class Exception.
D) they cannot be created

Question 26

C# does not guarantee that a finally block (if one is present)will be executed if a try block is exited via a return,break or continue statement.

Question 27

The catch handler that catches an exception of type Exception should be

A) last
B) anywhere
C) first
D) a catch handler that catches an exception of type Exception should not be used

Question 28

Variables local to a try block are usable in the corresponding catch
and finally blocks.

Question 29

After a finally block has finished executing:

A)control proceeds to the first statement after the finally block.
B)control returns to the throw point.
C)the app exits.
D)control proceeds to the first statement after the last catch block.

Question 30

In order to tell the user what happened in an exception you must

A) pop the exception
B) toss the exception
C) access Exception properties
D) throw the exception

Question 31

A catch block can use a concise notation to catch exceptions related by inheritance.

Question 32

Which of the following statements is true

A)The throw statement is used to throw an exception.
B)The throw statement is used to specify that a method will throw an exception.
C)The throw statement is used to access an exception parameter.
D)All of the above.

Question 33

If an exception handler is to catch a variety of exceptions,use a comma-separated list of catch arguments in the catch handler.

Question 34

The finally block is an ideal location for code that releases resources to prevent "resource leaks."

Question 35

If a finally block appears after the last catch block,it is executed only if an ex
ception is thrown.

Question 36

Which of the following statements is true

A) The code in a finally block is executed only if an exception occurs.
B) The code in a finally block is executed only if an exception does not occur.
C) The code in a finally block is executed only if there are no catch blocks.
D) None of the above are true.

Question 37

In order to display the error message generated by an exception,you use:

A) the Message method of class Exception
B) the Message property of class Exception
C) the ErrorMessage method of class Exception
D) the ErrorMessage property of class Exception

Question 38

Runtime exceptions can usually be fixed by eliminating coding errors.

Question 39

Exception handlers typically access objects in their try blocks to deter
mine the causes of the exceptions.

Question 40

A NullReferenceException is thrown when there's an attempt to use a reference that points to nothing.

Question 41

Stack unwinding is the process that attempts to locate an appropriate catch handler for an uncaught exception.

Question 42

The constructor method for an exception class should be overloaded to allow the customizing of the display message.

Question 43

Programmer-defined exception classes typically should contain 3 constructors:

A) a default constructor, a constructor that receives a string for the error message and a constructor that receives an Exception argument of the inner exception object
B) a default constructor, a constructor that receives a string and a constructor that receives both a string and an exception
C) a constructor that receives a string, a constructor that receives an exception and a constructor that receives both
D) a default constructor, a constructor that receives a string and a constructor that receives a number indicating the line number where the exception occurred

Question 44

By convention,the name of each user-defined exception should end with Exception.

Question 45

The StackTrace property keeps track of all the method calls that occur in a program,and that's how a program knows which method caused the error.

Question 46

The Message property of an exception is what is displayed to the user should that exception be thrown.

Question 47

Each Exception should have three constructors: A default constructor,one that receives a string,and one that receives a string and an exception.

Question 48

Resource de-allocation should be done explicitly in the finally block.

Question 49

Which of the following is not a property of Exception

A) HelpLink
B) Source
C) TargetSite
D) PrintError

Question 50

User-defined exceptions should be derived from the:

A) ApplicationException class.
B) ConsoleException class.
C) Exception class.
D) SystemException class.

Question 51

Which of the following statements is false

A) Prior to C# 6, you could catch an exception based only on its type.
B) C# 6's exception filters enable you to catch an exception based on a catch's exception type and a condition that's specified with a when clause.
C) You also can specify an exception filter for a general catch clause that does not provide an exception type.
D) If an exception filter's condition is false, the exception will not be caught and the original exception's stack-trace information will be deleted.

Question 52

There can be no code in between try/catch/finally blocks.

Question 53

The finally block is executed only if no error was reached in the try block.

Question 54

The process that attempts to locate an appropriate catch handler for an uncaught exception is known as:

A) laddering
B) stack winding
C) stack unwinding
D) stack traversing

Question 55

Which of the following statements is false

A) The HasValue property returns true if a nullable-type variable contains a value; otherwise, it returns false.
B) The Value property returns the nullable-type variable's underlying value.
C) The null coalescing operator (
D) All of the above statements are true.

Question 56

Which of the following statements is false

A) C# 6's null-conditional operator (
B) A nullable type is a value type that also can be null.
C) You specify a nullable type by following a value type's name with a question mark (
D) The GetValueOrDefault method checks whether a nullable-type variable contains a value. If so, the method returns that value; otherwise, it returns the value type's default value.

Question 57

Which of the following statements is false

A) Typically resource-release code should be placed in a finally block to ensure that a resource is released, regardless of whether there were exceptions when the resource was used in the corresponding try block.
B) The using statement simplifies writing code in which you obtain a resource, use the resource in a try block and release the resource in a corresponding finally block.
C) A file-processing app could process a file with a using statement to ensure that the file is closed properly when it's no longer needed.
D) The resource in a using statement must be an object that implements the IDiscardable interface.

Question 58

Consider the following code segment:
{
Var exampleObject = new ExampleClass();
Try
{
ExampleObject.SomeMethod();
}
Finally
{
If (exampleObject != null)
{
ExampleObject.Dispose();
}
}
}
Which of the following using statements is equivalent to the preceding code segment

A) try using (var exampleObject = new ExampleClass())
{
ExampleObject.SomeMethod(); // do something with exampleObject
}
B) using (var exampleObject = new ExampleClass())
{
ExampleObject.SomeMethod(); // do something with exampleObject
}
C) using (var exampleObject = new ExampleClass())
{
ExampleObject.SomeMethod(); // do something with exampleObject
ExampleObject.Dispose();
}
D) try using (var exampleObject = new ExampleClass())
{
ExampleObject.SomeMethod(); // do something with exampleObject
ExampleObject.Dispose();
}