The following is a practice quiz for one of my courses. I have taken it myself, but want to verify if my answers are correct and therefore would like anyone who is familiar with the subject material (Java programming) to provide their answers in order to compare.
PRACTICE QUIZ
1) Insert the missing code in the following code fragment. This fragment is intended to read an input file.
public static void main(String[] args) throws FileNotFoundException
{
String inputFileName = "dataIn.txt";
String outputFileName = "dataOut.txt";
File inputFile = new File(inputFileName);
Scanner in = _______________;
. . .
}
a) new Scanner(inputFileName)
b) new Scanner(outputFileName)
c) new Scanner(inputFile)
d) new Scanner(System.in)
2) Insert the missing code in the following code fragment. This fragment is intended to read a file and write to a file.
public static void main(String[] args) throws FileNotFoundException
{
String inputFileName = "dataIn.txt";
String outputFileName = "dataOut.txt";
File inputFile = new File(inputFileName);
Scanner in = new Scanner(inputFile);
PrintWriter out = _____________;
. . .
}
a) new PrintWriter(outputFileName)
b) new Scanner(outputFileName)
c) new PrintWriter(outputFile)
d) new Scanner(outputFile)
3) Which of the following statements about using the PrintWriter object is correct?
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.
4) Under which condition will the PrintWriter constructor generate a FileNotFoundException?
a) If the output file cannot be opened or created due to a security error.
b) If the output file does not exist.
c) If the output file already exists, but has data in it.
d) If the output file already exists, but is empty.
5) Which of the following statements reflects the textbook's recommendations about closing files?
a) Both the input and the output file do not need to be explicitly closed in the program.
b) Only the input file must be explicitly closed in the program.
c) Only the output file must be explicitly closed in the program.
d) Both the input and the output file should be explicitly closed in the program.
6) Consider the following code snippet:
public static void main(String[] args) throws FileNotFoundException
Which of the following statements about this code is correct?
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 FileNotFoundException.
c) The main method should simply terminate if the FileNotFoundException occurs.
d) The main method will not terminate if any exception occurs.
7) The PrintWriter class is an enhancement of the ____ class.
a) Scanner
b) ReadStream
c) PrintStream
d) File
8) Consider the following code snippet.
PrintWriter outFile = new PrintWriter("dataOut.txt");
Which of the following statements about the PrintWriter object is correct?
a) If a file named "dataOut.txt" already exists, an exception will occur.
b) If a file named "dataOut.txt" already exists, existing data will be deleted before new data is added to the file.
c) If a file named "dataOut.txt" already exists, new data will be added to the end of the file.
d) If a file named "dataOut.txt" already exists, a new file named "dataOut_1.txt" will be created and used.
9) Which of the following statements about using a PrintWriter object is NOT true?
a) A PrintWriter will be automatically closed when the program exits.
b) Data loss may occur if a program fails to close a PrintWriter object before exiting.
c) PrintWriter is an enhancement of the PrintStream class.
d) A program can write to a PrintWriter using println.
10) When reading words using a Scanner object's next method, ____.
a) any characters at the beginning of the input that are considered to be white space are consumed and become part of the word being read.
b) any characters at the beginning of the input that are considered to be white space are consumed and do not become part of the word being read.
c) the program must discard white space characters at the beginning of the input before calling the next method.
d) any characters that are considered to be white space within the word become part of the word.