Question 1

The Scanner class's ____ method is used to specify a pattern for word boundaries when reading text.

Accepted Answer

The useDelimiter() method in the Scanner class is used to specify a pattern for word boundaries when reading text.

Question 2

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

The useDelimiter("[^A-Za-z]+") sets the delimiter to any sequence of non-alphabetic characters, meaning that only alphabetic characters will be read, and non-alphabetic characters will be ignored.

Question 3

Consider the following code snippet. Scanner in = new Scanner(. . .);
While (in.hasNextLine())
{
String input = in.nextLine();
}
Which of the following statements about this code is correct?

Accepted Answer

The code uses `in.nextLine()` which reads one line at a time from the input.

Question 4

Consider the following code snippet: Scanner in = new Scanner(. . .);
In)useDelimiter("[^0-9]+");
What characters will be ignored and not read in using this code?

Accepted Answer

The useDelimiter("[^0-9]+") sets the delimiter to any sequence of non-numeric characters, meaning only numeric characters will be read, and non-numeric characters will be ignored.

Question 5

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

words.hasNext() checks if there is another word in the line.

Question 6

Which String class method will remove spaces from the beginning and the end of a string?

Accepted Answer

The answer of Which String class method will remove spaces...

Question 7

Which of the following statements about white space in Java is correct?

Accepted Answer

In Java, white space includes spaces, tab characters, and newline characters, which are used to separate tokens in the code.

Question 8

Select an expression to complete the following statement, which is designed to construct a PrintWriter object to write the program output to a file named dataout.txt PrintWriter theFile = _______________________;

Accepted Answer

The correct way to construct a PrintWriter object for writing to a file is by using `new PrintWriter("dataout.txt")`.

Question 9

Consider the following code snippet: Scanner in = new Scanner(. . .);
In)useDelimiter("[^0-9A-Za-z]+");
What characters will be ignored and not read in using this code?

Accepted Answer

The useDelimiter("[^0-9A-Za-z]+") specifies that the delimiter is any sequence of characters that are not alphanumeric, meaning non-alphanumeric characters will be ignored.

Question 10

The ____ method of the Character class will indicate if a character contains white space.

Accepted Answer

The isWhiteSpace() method of the Character class returns true if the character is a whitespace character (space, tab, newline).

Question 11

Insert the missing code in the following code fragment. This fragment is intended to read all words from a text file. File inputFile = new File("dataIn.txt");
Scanner in = new Scanner(dataIn.txt);
While (____________)
{
String input = in.next();
System.out.println(input);
}

Accepted Answer

The method `in.hasNext()` checks if there is another word in the input, making it suitable for use in the while loop condition to read all words from the file.

Question 12

Assuming that inputFile is a Scanner object used to read words from a text file, select an expression to complete the following code segment, which counts the number of words in the input file.
Int count = 0;
While (inputFile.hasNext())
{
String word = _______________;
Count++;
}
System.out.println(count);

Accepted Answer

The method `inputFile.next()` reads the next word from the input file as a String, which is appropriate for counting words.

Question 13

When reading words using a Scanner object's next method, ____.

Accepted Answer

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.

Question 14

Assume that inputFile is a Scanner object used to read data from a text file which contains a series of double values. Select an expression to complete the following code segment, which reads the values and prints them in standard output, one per line, in a field 15 characters wide, with two digits after the decimal point. while (inputFile.hasNextDouble())
{
Double value = inputFile.nextDouble();
___________________________________ // statement do display double value
}

Accepted Answer

The answer of Assume that inputFile is a Scanner object...

Question 15

Consider the following code snippet: Scanner in = new Scanner(. . .);
While (in.hasNextLine())
{
String input = in.nextLine();
System.out.println(input);
}
Which of the following statements about this code is correct?

Accepted Answer

The code uses `in.nextLine()` to read an entire line from the input source in each iteration of the loop.

Question 16

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

The method `inputFile.hasNextInt()` checks if the next token in the input is an integer, which is suitable for counting integer values.

Question 17

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

The answer of Insert the missing code in the following...

Question 18

When reading words with a Scanner object, a word is defined as ____.

Accepted Answer

In Java's Scanner class, a word is defined as any sequence of characters that is not white space. This means it can include letters, numbers, and punctuation.

Question 19

Consider the following code snippet. File inputFile = new File("dataIn.txt");
Scanner in = new Scanner(inputFile);
While (in.hasNext())
{
String input = in.next();
}
Which of the following statements about this code is correct?

Accepted Answer

The code uses `in.next()`, which reads one word at a time from the input file.

Question 20

Which of the following patterns should be used for the delimiter to read one character at a time using a Scanner object's next method?

Accepted Answer

The pattern "" (an empty string) as a delimiter will make the Scanner read one character at a time.

Quiz 11: Inputoutput and Exception Handling

The Scanner class's ____ method is used to specify a pattern for word boundaries when reading text.

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?

Consider the following code snippet. Scanner in = new Scanner(. . .) ; While (in.hasNextLine() ) { String input = in.nextLine() ; } Which of the following statements about this code is correct?

Consider the following code snippet: Scanner in = new Scanner(. . .) ; In) useDelimiter("[^0-9]+") ; What characters will be ignored and not read in using this code?

Which String class method will remove spaces from the beginning and the end of a string?

Which of the following statements about white space in Java is correct?

Select an expression to complete the following statement, which is designed to construct a PrintWriter object to write the program output to a file named dataout.txt PrintWriter theFile = _______________________;

Consider the following code snippet: Scanner in = new Scanner(. . .) ; In) useDelimiter("[^0-9A-Za-z]+") ; What characters will be ignored and not read in using this code?

The ____ method of the Character class will indicate if a character contains white space.

Insert the missing code in the following code fragment. This fragment is intended to read all words from a text file. File inputFile = new File("dataIn.txt") ; Scanner in = new Scanner(dataIn.txt) ; While (____________) { String input = in.next() ; System.out.println(input) ; }

When reading words using a Scanner object's next method, ____.

Consider the following code snippet: Scanner in = new Scanner(. . .) ; While (in.hasNextLine() ) { String input = in.nextLine() ; System.out.println(input) ; } Which of the following statements about this code is correct?

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) ; }

When reading words with a Scanner object, a word is defined as ____.

Consider the following code snippet. File inputFile = new File("dataIn.txt") ; Scanner in = new Scanner(inputFile) ; While (in.hasNext() ) { String input = in.next() ; } Which of the following statements about this code is correct?

Which of the following patterns should be used for the delimiter to read one character at a time using a Scanner object's next method?