Deck 10: Exceptions

Question 1

Which of the following exceptions are unchecked?

A) RuntimeException
B) IllegalAccessException
C) NoSuchMethodException
D) ClassNotFoundException
E) none of the above

Answer 1

A
Explanation: All subclasses of the RuntimeException class are unchecked.

Question 2

Every line in a catch block is guaranteed to be executed in all situations.

Answer 2

False
Explanation: A catch block may not be executed at all. It is only executed when an exception is thrown. All lines in a finally block are guaranteed to be executed.

Question 3

A(n) ____________________ can be used to find the exact line where an exception was thrown during program execution.

A) interface
B) call-stack trace
C) try block
D) catch block
E) none of the above

Answer 3

B
Explanation: A call-stack indicates the exact line where an exception is thrown.

Question 4

Which of the following represents the standard input stream?

A) System.in
B) System.out
C) System.err
D) System.instream
E) System.outstream

Question 5

A(n) _____________________ is an object that defines an unusual or erroneous situation that is typically recoverable.

A) error
B) exception
C) interface
D) try block
E) catch block

Question 6

A(n) ________________ is an ordered sequence of bytes.

A) exception
B) error
C) input-output flow
D) stream
E) none of the above

Question 7

A(n) ____________________ is used to identify a block of statements that may cause an exception.

A) call-stack trace
B) error
C) catch block
D) try block
E) none of the above

Question 8

Which of the following file streams should be explicitly closed to ensure that written data is properly retained?

A) output
B) input
C) error
D) writable
E) readable

Question 9

Which of the following exception types must always be caught unless they are contained in methods that throw them in the method header?

A) file stream
B) IO
C) checked
D) unchecked
E) none of the above

Question 10

The Exception class and the Error class are subclasses of the ___________________ class.

A) Throwable
B) Catchable
C) RuntimeProblem
D) CompilerProblem
E) none of the above

Question 11

Unchecked exceptions must be caught or propogated, or a program will not compile.

Question 12

The _________________ statement is used to begin exception propogation.

A) propogate
B) relay
C) throw
D) except
E) send

Question 13

Every line of a(n) __________________ is executed no matter what exceptions are thrown.

A) try block
B) call stack trace
C) catch block
D) interface
E) finally block

Question 14

If an exception is not caught, a program will __________________________ .

A) not compile
B) terminate abnormally
C) print a message and continue executing
D) all of the above
E) neither a, b nor c

Question 15

A finally clause is always required in a try-catch block.

Question 16

Attempting to divide by zero will result in an Error being thrown, not an Exception.

Question 17

A(n) _____________________ is an object that defines an erroneous situation from which the program usually cannot recover.

A) error
B) exception
C) interface
D) try block
E) catch block

Question 18

Which of the following methods are part of the Exception class and can be used to give information about a thrown exception?

A) getInfo
B) printInfo
C) printStackTrace
D) getStackTrace
E) none of the above

Question 19

The Exception class is a subclass of the Object class.

Question 20

A(n) ____________________ is used to specify how certain exceptions should be handled.

A) finally block
B) try block
C) catch block
D) error
E) none of the above

Question 21

What is a catch clause?

Question 22

The getMessage method of the Exception class prints out the stack trace, which helps the user to track down the source of the exception.

Question 23

When accessing an element of an array, if the index is outside of the range of the indexes of the array, an exception is thrown.

Question 24

What are the standard I/O streams?

Question 25

Is the Exception class a subclass of the Error class? Explain.

Question 26

A throw statement is used to begin exception propagation.

Question 27

Write a short snippet of code that converts the first element of the String[] args array to an integer. It should catch an exception and print out a message if the first element cannot be converted to an integer.

Question 28

Consider the following code fragment.
String s;
for(int i = 0; i < s.length(); i++)
System.out.println(s.charAt(i));
What exception will be thrown by this code and why?

Question 29

What is exception prorogation, and how does it work in Java?

Question 30

What is the difference between a checked exception and an unchecked exception?

Question 31

Give two examples of methods in the Exception class that can be used to output information about the Exception.

Question 32

Consider the following code fragment.
int [] a = new int[50];
a[50] = 100;
Will this code fragment throw an exception? Explain.

Question 33

Write a code fragment that will throw an ArithmeticException. Your code fragment should not use the throw statement.

Question 34

How is a finally clause different from a try block and a catch clause?

Question 35

What is a try block?

Question 36

In practice, it is important to catch all exceptions that might be thrown by a program.

Question 37

How does a method throw an exception?

Question 38

Is an exception an object? Explain.

Question 39

What is the difference between an exception and an error?

Question 40

An exception will be propagated until it is caught and handled or until it is passed out of the main method.