Question 1

Assume that inputFile is a Scanner object used to read data from a text file which contains a number of lines. Some lines contain an alphabetic string, while others contain a single integer value. Select an expression to complete the following code segment, which counts the number of integer values in the input file.
Int count = 0;
While (inputFile.hasNextLine())
{
If (________________________________)
{
Count++;
}
InputFile.nextLine();
}
System.out.println(count);

Accepted Answer

A)   inputFile.hasNext() 
B)   inputFile.hasNextInt() 
C)   inputFile.nextInt() 
D)   Character.isDigit(inputFile.next() )  B

Question 2

Which of the following statements about using the PrintWriter object is correct?

Accepted Answer

A)   If the output file already exists, the new data will be appended to the end of the file.
B)   If the output file does not exist, a FileNotFoundException will occur.
C)   If the output file already exists, the existing data will be discarded before new data are written into the file.
D)   If the output file does not exist, an IllegalArgumentException will occur. C

Question 3

Insert the missing code in the following code fragment. This fragment is intended to read an input file named hoursWorked.txt. You want the program to terminate if the file does not exist. public static void main(String[] args) ______________
{
File inputFile = new File("hoursWorked.txt");
Scanner in = new Scanner(inputFile);
) . .
}

Accepted Answer

A)   catch FileMissingException
B)   catch FileNotFoundException
C)   throws FileMissingException
D)   throws FileNotFoundException D

Question 4

Consider the following code snippet: try
{
PrintWriter outputFile = new PrintWriter(filename);
Try
{
WriteData(outputFile);
}
Finally
{
OutputFile.close();
}
}
Catch (IOException exception)
{
) . .
}
Which of the following statements about this code is correct?

Accepted Answer

A)   The file will be closed regardless of when the exception occurs.
B)   The file will be closed if the PrintWriter constructor throws an exception.
C)   The file will be closed if the writeData()  statement throws an exception.
D)   It is not possible to determine whether the file will be closed if an exception occurs.

Question 5

When writing a method, which of the following statements about exception handling is true?

Accepted Answer

A)   The throws clause must list all checked exceptions that this method may throw, and may also list unchecked exceptions.
B)   The throws clause must list all unchecked exceptions, and may also list checked exceptions that this method may throw.
C)   The throws clause must list all checked exceptions, but cannot list unchecked exceptions.
D)   The throws clause must list all unchecked exceptions, and cannot list checked exceptions.

Question 6

Which of the following statements about exception handling is recommended by the textbook?

Accepted Answer

A)   All exceptions should be handled where they are first detected.
B)   All exceptions should be handled at the top of the chain of methods.
C)   Throw an exception only when the problem can be handled.
D)   Throw an exception as soon as a problem is detected, but only catch exceptions when the problem can be handled.

Question 7

Insert the missing code in the following code fragment. This fragment is intended to read characters from a text file. Scanner in = new Scanner(. . .);
In)useDelimiter("");
While (in.hasNext())
{
Char ch = ____________;
System.out.println(ch);
}

Accepted Answer

A)   in.getNext() 
B)   in.next() 
C)   in.next.charAt(0) 
D)   in.nextChar()

Question 8

Your program will read in an existing text file. You want the program to terminate if the file does not exist. Which of the following indicates the correct code for the main method header?

Accepted Answer

A)   public static void main(String[] args)  throws FileMissingException
B)   public static void main(String[] args)  throws FileNotFoundException
C)   public static void main(String[] args) 
D)   public static void main(String[] args)  throws UnknownFileException

Question 9

Which Java class implements a file dialog box for selecting a file by a program with a graphical user interface?

Accepted Answer

A)   JOptionPane
B)   JFileOption
C)   JFilePane
D)   JFileChooser

Question 10

What is the purpose of the throw statement?

Accepted Answer

A)   It is used to pass arguments to another method.
B)   It is used to detect an error situation.
C)   It is used to pass control to an error handler when an error situation is detected.
D)   It is used to discard erroneous input.

Question 11

Consider the following code snippet: Scanner in = new Scanner(. . .);
) . .
If (in.hasNext())
{
Throw new IOException("End of file expected");
}
Which of the following statements about this code is correct?

Accepted Answer

A)   The program will display the message "End of file expected" if there is no data.
B)   The program will throw an exception if there is no data.
C)   The program will display the message "End of file expected" if there is data left in the input when the if statement is executed.
D)   The program will throw an exception if there is data left in the input when the if statement is executed.

Question 12

Consider the following code snippet: public static void main(String[] args) throws IOException
Which of the following statements about this code is correct?

Accepted Answer

A)   The main method is designed to catch and handle all types of exceptions.
B)   The main method is designed to catch and handle the IOException.
C)   The main method should simply terminate if the IOException occurs.
D)   The main method will not terminate if any exception occurs.

Question 13

Consider the following code snippet:
If (in.hasNextDouble())
{
Number = in.nextDouble();
}
Result = in.next();
If the input contains the characters 626.14 average, what values will number and result have after this code is executed?

Accepted Answer

A)   number will contain the value 626 and result will contain the value 14.
B)   number will contain the value 626.14 and result will contain the value average.
C)   number will contain the value 0 and result will contain the value 626.14.
D)   number will contain the value 0 and result will contain the value average.

Question 14

Consider the following code snippet written in Java 7: try (PrintWriter outputFile = new PrintWriter(filename))
{
WriteData(outputFile);
}
Which of the following statements about this Java 7 code is correct?

Accepted Answer

A)   The program will terminate with an unhandled exception if the PrintWriter constructor fails.
B)   The close method of the outputFile object will be automatically invoked when the try block ends, but only if no exception occurred.
C)   The close method of the outputFile object will be automatically invoked when the try block ends, but only if an exception occurs.
D)   The close method of the outputFile object will be automatically invoked when the try block ends, whether or not an exception has occurred.

Question 15

Consider the following code snippet. File hoursFile = new File("hoursWorked.txt");
Your program must read the contents of this file using a Scanner object. Which of the following is the correct syntax for doing this?

Accepted Answer

A)   Scanner in = new Scanner("hoursWorked.txt") ;
B)   Scanner in = Scanner("hoursWorked.txt") ;
C)   Scanner in = new Scanner(hoursFile) ;
D)   Scanner in = Scanner.open(hoursFile) ;

Question 16

Assume that inputFile is a Scanner object used to read data from a text file which contains a number of lines. Each line contains an arbitrary number of words, with at least one word per line. Select an expression to complete the following code segment, which prints the last word in each line. while (inputFile.hasNextLine())
{
String word = "";
String line = inputFile.nextLine();
Scanner words = new Scanner(line);
While (_________________)
{
Word = words.next();
}
System.out.println(word);
}

Accepted Answer

A)   words.hasNext() 
B)   words.hasNextInt() 
C)   line.hasNext() 
D)   inputFile.hasNext()

Question 17

You wish to use the Scanner class's nextInt() method to read in whole numbers. To avoid exceptions that would occur if the input is not a whole number, you should use the ____ method before calling nextInt.

Accepted Answer

A)   hasNext() 
B)   hasNextInteger() 
C)   hasIntegerValue() 
D)   hasNextInt()

Question 18

Insert the missing code in the following code fragment. This code is intended to open a file and handle the situation where the file cannot be found. public void String readFile() throws IOException
{
File inputFile = new File(. . .);
Scanner in = new Scanner(inputFile);
Try
{
While (in.hasNext())
{
) . .
}
}
Finally
{
___________________
}
}

Accepted Answer

A)   catch (IOException exception) 
B)   catch (FileNotFound exception) 
C)   catch (IllegalArgumentException exception) 
D)   in.close()

Question 19

Consider the following code snippet: Scanner in = new Scanner(. . .);
In)useDelimiter("[^A-Za-z]+");
What characters will be ignored and not read in when using this code?

Accepted Answer

A)   Only alphabetic characters will be ignored.
B)   Only numeric characters will be ignored.
C)   Only non-alphabetic characters will be ignored.
D)   Only non-numeric characters will be ignored.

Question 20

Which method of an exception object will retrieve a description of the exception that occurred?

Accepted Answer

A)   printStackTrace() 
B)   printMessage() 
C)   getMessage() 
D)   getDescription()

Exam 11: Inputoutput and Exception Handling

Which of the following statements about using the PrintWriter object is correct?

Consider the following code snippet: try { PrintWriter outputFile = new PrintWriter(filename) ; Try { WriteData(outputFile) ; } Finally { OutputFile.close() ; } } Catch (IOException exception) { ) . . } Which of the following statements about this code is correct?

When writing a method, which of the following statements about exception handling is true?

Which of the following statements about exception handling is recommended by the textbook?

Insert the missing code in the following code fragment. This fragment is intended to read characters from a text file. Scanner in = new Scanner(. . .) ; In) useDelimiter("") ; While (in.hasNext() ) { Char ch = ____________; System.out.println(ch) ; }

Your program will read in an existing text file. You want the program to terminate if the file does not exist. Which of the following indicates the correct code for the main method header?

Which Java class implements a file dialog box for selecting a file by a program with a graphical user interface?

What is the purpose of the throw statement?

Consider the following code snippet: Scanner in = new Scanner(. . .) ; ) . . If (in.hasNext() ) { Throw new IOException("End of file expected") ; } Which of the following statements about this code is correct?

Consider the following code snippet: public static void main(String[] args) throws IOException Which of the following statements about this code is correct?

Consider the following code snippet: If (in.hasNextDouble() ) { Number = in.nextDouble() ; } Result = in.next() ; If the input contains the characters 626.14 average, what values will number and result have after this code is executed?

Consider the following code snippet written in Java 7: try (PrintWriter outputFile = new PrintWriter(filename) ) { WriteData(outputFile) ; } Which of the following statements about this Java 7 code is correct?

Consider the following code snippet. File hoursFile = new File("hoursWorked.txt") ; Your program must read the contents of this file using a Scanner object. Which of the following is the correct syntax for doing this?

You wish to use the Scanner class's nextInt() method to read in whole numbers. To avoid exceptions that would occur if the input is not a whole number, you should use the ____ method before calling nextInt.

Consider the following code snippet: Scanner in = new Scanner(. . .) ; In) useDelimiter("[^A-Za-z]+") ; What characters will be ignored and not read in when using this code?

Which method of an exception object will retrieve a description of the exception that occurred?