Deck 21: Advanced Inputoutputetext Only

Question 1

Which class is used for input of text data?
A.OutputStream
B.Writer
C.InputStream
D.Reader

Answer 1

Reader

Question 2

Which class is used for output of binary data to a file?
A.Writer
B.FileOutputStream
C.FileOutput
D.Scanner

Answer 2

FileOutputStream

Question 3

Which class is used for input of binary data from a file?
A.FileInput
B.FileInputStream
C.Scanner
D.Reader

Answer 3

FileInputStream

Question 4

Fill in the blank in the following code snippet to create an object for reading binary data from a disk file, named input.bin?
try (______________________________)
{
Process input
}
A.FileReader in = new FileReader("input.bin");
B.FileWriter in = new FileWriter("input.bin");
C.PrintWriter in = new PrintWriter("input.bin");
D.FileInputStream in = new FileInputStream("input.bin");

Question 5

Which class is used for output of text data to a file?
A.FileWriter
B.FileOutputStream
C.PrintWriter
D.RandomAccessFile

Question 6

In text format, data items are represented in human-readable form, as a sequence of ____________________.
A.integers
B.strings
C.bytes
D.characters

Question 7

Which file storage method stores data in bytes?
A.binary
B.byte
C.text
D.object

Question 8

Which class is used for input of binary data?
A.OutputStream
B.Reader
C.InputStream
D.Writer

Question 9

Which class is used for input of text data from a file?
A.FileWriter
B.RandomAccessFile
C.FileInputStream
D.Scanner

Question 10

Which class is used for output of text data?
A.OutputStream
B.Reader
C.InputStream
D.Writer

Question 11

Streams access sequences of ____.
A.bytes
B.files
C.characters
D.strings

Question 12

Which class is used for output of binary data?
A.Reader
B.Writer
C.OutputStream
D.InputStream

Question 13

Which file storage method is in human-readable form?
A.byte
B.text
C.binary
D.object

Question 14

Which of these classes access sequences of characters?
I readers
II writers
III streams
A.II and III only
B.II only
C.I only
D.I and II only

Question 15

If you store information in binary form, as a sequence of bytes, you will use the ____ class(es) and their subclasses.
A.Reader and Writer
B.PrintWriter
C.Serializable
D.InputStream and OutputStream

Question 16

A byte is composed of ____ bits and can denote ____ values.
A.8, 256
B.4, 256
C.8, 1024
D.2, 19

Question 17

If you access and store information in binary form in files, you will use the ____ class(es).
A.Scanner and PrintWriter
B.PrintStream
C.FileInputStream and FileOutputStream
D.Reader and Writer

Question 18

The ______ method returns an integer, either -1 (at the end of the file) or a byte between 0 and 255.
A.InputStream.read
B.OutputStream.write
C.Reader.length
D.Scanner.next

Question 19

Readers and writers access sequences of ____.
A.bytes
B.files
C.streams
D.characters

Question 20

Which is an advantage of storing numbers in binary format?
I fast access
II less storage needed
III easy to read in a text editor
A.I and II only
B.I only
C.III only
D.I and III only

Question 21

How many bytes does the read method in the FileInputStream class get from the file?
A.1
B.8
C.4
D.2

Question 22

The values of the byte type range from ____ to ____.
A.-128, 127
B.0, 256
C.-128, 128
D.0, 255

Question 23

What is the lowest value for a signed (negative and positive) byte?
A.-128
B.-256
C.-255
D.-127

Question 24

Fill in the blank in the following code snippet to create an object for writing binary data to a disk file, named output.bin?
try (______________________________)
{
Process output
}
A.Writer out = new Writer("output.bin");
B.PrintWriter out = new PrintWriter("output.bin");
C.FileOutputStream out = new FileOutputStream("output.bin");
D.FileWriter out = new FileWriter("output.bin");

Question 25

A Caesar cipher uses a shift of each character by a key with a value between 1 and 255.An a with a shift of 3 becomes a d.A z with a shift of 3 would become a c, wrapping around the alphabet.Which key should you use to encrypt picture into mfzqrob?
A.19
B.-3
C.-19
D.3

Question 26

You would need a Caesar cipher with a shift of __________ to decrypt the text T U V W X Y Z A B C D E F G H I J K L M N O P Q R S so that it reads A B C D E F G H I J K L M N O P Q R S T U V W X Y Z.
A.19
B.7
C.-19
D.20

Question 27

Which statement is NOT correct about the OutputStream.write method?
A.The method writes an int (4 bytes) to the output stream.
B.The type of the parameter for the method is int.
C.The FileOutputStream class overrides the method to write a single byte to a file.
D.The value of the parameter must be between the values of 0 and 255.

Question 28

A Caesar cipher uses a shift of each character by a key with a value between 1 and 255.An a with a shift of 3 becomes a d.A z with a shift of 3 would become a c, wrapping around the alphabet.Which is the decryption of exmmv for a key = -3?
A.bujjs
B.atiir
C.cvkkt
D.happy

Question 29

A Caesar cipher uses a shift of each character by a key with a value between 1 and 255.An a with a shift of 3 becomes a d.A z with a shift of 3 would become a c, wrapping around the alphabet.Which is the encryption of shadow for a key = 3?
A.adowsha
B.vkdgrz
C.vjegrz
D.ukdgry

Question 30

A Caesar cipher uses a shift of each character by a key with a value between 1 and 255.An a with a shift of 3 becomes a d.For the encrypt method below, select the correct body.Assume the key shift property is accessible to the method.
public int encrypt(int b)
{
__________
}
A.return (b + key) % 256);
B.return (b + key % 26);
C.return (b + key);
D.return (b + 26 % key);

Question 31

Which class has a write method that writes a single byte?
A.Stream
B.PrintWriter
C.OutputStream
D.Writer

Question 32

What is the highest value for a signed (negative and positive) byte?
A.256
B.127
C.128
D.255

Question 33

In ____________ file access, the file is processed starting from the beginning.
A.binary
B.random
C.parallel
D.sequential

Question 34

In Java, the byte type is a(n) ____ type.
A.unsigned
B.positive
C.signed
D.negative

Question 35

What is returned by the read method when a FileInputStream has reached the end of the file?
A.0
B.-1
C.-2
D.'\n'

Question 36

Caesar cipher uses a shift of each character by a key with a value between 1 and 255.An a with a shift equal to 3 becomes a d.For the decrypt method below, select the correct body.Assume the key shift property is accessible to the method.
public int decrypt(int b)
{
__________
}
A.return (b - key);
B.return (b + key);
C.return (b - key % 26);
D.return (b - key) % 256);

Question 37

Why does FileInputStream override the read method from its superclass InputStream?
A.In order to read binary data.
B.In order to return a char.
C.To check for end of file.
D.To read data from a file.

Question 38

A Caesar cipher uses a shift of each character by a key with a value between 1 and 255.An a with a shift of 3 becomes a d.A z with a shift of 3 would become a c, wrapping around the alphabet.Which is the encryption of picture for a key = -3?
A.mfzqrob
B.erutcip
C.urepict
D.ngahspc

Question 39

You cannot read a ____________________ file with a text editor.
A.serial
B.binary
C.random
D.sequential

Question 40

The read method of the FileInputStream class reads binary data.What type is actually returned from a call to read?
A.int
B.String
C.byte
D.char

Question 41

In which of the following modes can a RandomAccessFile be opened?
I r
II rw
III w
A.I and III only
B.I only
C.I and II only
D.II only

Question 42

Which code moves the file pointer to the middle of a RandomAccessFile object, file?
A.file.seek(file.getFilePointer() / 2)
B.file.seek(file.length() / 2)
C.file.seek(0L)
D.file.seek(file.length())

Question 43

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage.If the file pointer is currently on the 24th record, which expression represents the offset to the beginning of the 25th record?
A.MyData.RECORD_SIZE * 2
B.MyData.RECORD_SIZE + file.getFilePointer()
C.MyData.RECORD_SIZE + 1
D.file.getFilePointer()

Question 44

Given a RandomAccessFile that stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage, which expression gets the offset to the beginning of the 25th record?
A.MyData.RECORD_SIZE * 25
B.MyData.RECORD_SIZE + 25
C.MyData.RECORD_SIZE++
D.MyData.RECORD_SIZE * 24

Question 45

Which of the following classes are used with data in binary form?
I FileInputStream
II FileReader
III RandomAccessFile
A.I and III only
B.I and II only
C.II and III only
D.I only

Question 46

Which is NOT a method in the RandomAccessFile class?
A.seek
B.length
C.getFilePointer
D.scan

Question 47

__________ access allows file access at arbitrary locations, without first reading the bytes preceding the access location.
A.Sequential
B.Serial
C.Random
D.Binary

Question 48

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData, each needing MyData.RECORD_SIZE bytes for storage.Which expression calculates the number of records in the file?
A.MyData.RECORD_SIZE * file.length()
B.file.length() / MyData.RECORD_SIZE
C.MyData.RECORD_SIZE + file.getFilePointer()
D.file.seek(0L) / MyData.RECORD_SIZE

Question 49

Assume we have a RandomAccessFile object, file, which stores a set of records of class MyData.The size of each record is MyData.RECORD_SIZE.Assume MyData has read and write methods, both of which take a RandomAccessFile as an argument.Method write writes the object at the current location.Method read reads the record from current location of the file into the object.If we are currently at the beginning of the 25th record, which code correctly modifies the 25th record by changing its color to Color.yellow through the setColor method?

Question 50

A file pointer is a position in a random access file.Because files can be very large, the file pointer is of type _______.
A.int
B.double
C.long
D.byte

Question 51

Assume we have a RandomAccessFile object, file, that stores a set of records of class MyData.The size of each record is MyData.RECORD_SIZE.Assume MyData has read and write methods both of which take a RandomAccessFile as an argument.Method write writes the object at the current location.Method read reads the record from current location of the file into the object.If we are currently at the beginning of the 1st record, which code correctly modifies the 2nd record by changing its color to Color.red through the setColor method?

Question 52

Which method in the RandomAccessFile class provides for random access?
A.goto
B.offset
C.seek
D.move

Question 53

Based on the code below, the statement that would move the file pointer to byte n counted from the beginning of the file is ___________________.
RandomAccessFile test = new RandomAccessFile("record.bat", "r");
A.test.getFilePointer(n);
B.test.length() - n;
C.test.seek(n);
D.test.getFilePointer();

Question 54

The readInt and writeInt methods of the RandomAccessFile class read and write integers as ____ quantities.
A.two-byte
B.four-byte
C.eight-byte
D.six-byte

Question 55

When storing numbers in a file with fixed record sizes, it is easier to store them in __________ format.
A.character
B.binary
C.serializable
D.text

Question 56

The readDouble and writeDouble methods of the RandomAccessFile class, process double precision floating-point numbers as ____ quantities.
A.ten-byte
B.two-byte
C.four-byte
D.eight-byte

Question 57

Which statement about object streams is NOT correct?
A.Use object input streams to load the saved objects.
B.You must cast the returned result from the readObject method.
C.Any object can be saved to an object output stream.
D.Use object output streams to save all instance variables of an object automatically.

Question 58

What do we call the measure in bytes of the file pointer from the beginning of a RandomAccessFile?
A.size
B.seek
C.latency
D.offset

Question 59

Which is not a method available in the RandomAccessFile class?
A.readDouble
B.open
C.readInt
D.close

Question 60

Which method moves the file pointer in a RandomAccessFile?
A.close
B.seek
C.length
D.getFilePointer

Question 61

Which of the following cannot be serialized?
I ArrayList
II String
III Integer
A.I only
B.III only
C.II and III only
D.All can be serialized

Question 62

What type is returned from a call to the ObjectInputStream.readObject method when reading a String from an object stream?
A.String
B.ObjectStream
C.Object
D.char

Question 63

How many methods are required to implement the Serializable interface?
A.3
B.1
C.0
D.2

Question 64

Every object is assigned a serial number on the stream.What might be the result if the same object is saved twice?
A.A performance decrease.
B.Running out of serial numbers.
C.The object will have two serial numbers.
D.Only the serial number is written out the second time.

Question 65

Which interface allows classes to be written to an ObjectOutputStream?
A.Streaming
B.Serializable
C.Objectifiable
D.Objective

Question 66

In which package are the following types found: Path, Paths, Files?
A.java.io.file
B.java.nio
C.java.nio.file
D.java.io

Question 67

If serializing object obj requires 12 bytes, how many bytes are required to serialize obj 3 times?
A.12 bytes plus 3 serial numbers of obj
B.36 bytes
C.12 bytes
D.12 bytes plus 2 serial numbers of obj

Question 68

Which code reads an array of Student objects from a file named studentFile.bin? We ignore exceptions in this problem.

Question 69

Fill in the blank in the following code snippet.
______ myVariable = Paths.get("filename.txt");
A.FileReader
B.File
C.Path
D.FileInputStream

Question 70

Which of the following classes are related through inheritance?
I InputStream
II InputStreamReader
III ObjectInputStream
A.I, II and III
B.I and III only
C.II and III only
D.I and II only

Question 71

What type of object describes the location of a file or directory?
A.Path
B.Paths
C.Files
D.Directories

Question 72

If we want to write objects to a file, what type of object should be passed to the ObjectOutputStream constructor?
A.FileOutputStream
B.ObjectStream
C.ObjectInputStream
D.FileStream

Question 73

Objects are saved in ___________ format in object streams.
A.integer
B.binary
C.stream
D.character

Question 74

Which code stores an array studentArray of Student objects in a file named studentFile.bin? We ignore exceptions in this problem.

Question 75

Which of the following is NOT a method of the Path type?
A.walk
B.getParent
C.resolve
D.getFileName

Question 76

The two IO classes used for serialization are _______ and ________.
A.Reader, Writer
B.ObjectInputStream, ObjectOutputStream
C.FileReader, FileWriter
D.Scanner, PrintWriter

Question 77

Objects saved to an object stream must belong to classes that ______________.
A.implement the ObjectInputStream interface
B.are RandomAccessFile objects
C.implement the Serializable interface
D.are abstract

Question 78

Which expression returns a String representing the full path to the file filename.txt?
A.Paths.get("filename.txt")
B.Paths.get("filename.txt").toString()
C.Paths.get("filename.txt").toAbsolutePath()
D.Paths.get("filename.txt").toAbsolutePath().toString()

Question 79

Which methods are not in the Serializable interface?
I readObject
II writeObject
III serializeObject
A.II and III only
B.I, II, and III
C.I and II only
D.I only

Question 80

If you write a simple Student class, what must you do in order to write Student objects to an ObjectOutputStream?
A.Make all class variables primitive.
B.Implement Streamable.
C.Code a write method.
D.Implement Serializable.