Deck 2: Console Input and Output

Question 1

If a hyphen is added after the % in a format specifier,the output will be _________.
(a)Left justified
(b)Right justified
(c)Centered
(d)None of the above

Answer 1

A

Question 2

Valid arguments to the System.out object's println method include:
(a)"Anything with double quotes"
(b)String variables
(c)Variables of type int
(d)All of the above

Answer 2

D

Question 3

Efficiency is lost in importing the entire package instead of importing the classes you use.

Answer 3

False

Question 4

The Scanner class has a method next that allows an entire line of string text to be read.

Question 5

Write Java statements to apply currency formatting to the number 100.Indicate the package you need to import.

Question 6

Every Java program automatically imports the java.util package.

Question 7

Which statement or group of statements produces the output: Java programming is fun!
(a)System.out.print(Java programming); System.out.print(is fun!);
(b)System.out.println(Java programming is fun!);
(c)System.out.println("Java programming"); System.out.println(" is fun!");
(d)System.out.print("Java programming") System.out.println(" is fun!");

Question 8

The class NumberFormat allows you to specify a constant representing which country's currency format should be used.To use this constant you must import:
(a)java.util.Locale
(b)java.util.Currency
(c)java.util.Properties
(d)None of the above.

Question 9

The Java method printf is based on the ________ language.
(a)Pascal
(b)C++
(c)C
(d)ADA

Question 10

Standard code libraries in Java are called:
(a)Methods
(b)Classes
(c)Packages
(d)Statements

Question 11

Echoing input is good programming practice because it can reveal problems in the input.

Question 12

What Java package includes the class Scanner?
(a)awt
(b)swing
(c)io
(d)util

Question 13

Write a Java statement to display your name in the console window.

Question 14

The method printf is used the same way as the method println but has the added feature that allows you to add formatting instructions.

Question 15

The statement: System.out.printf("%6.2f",597.7231); displays:
(a)597.723
(b)597.72
(c)000597.72
(d)None of the above

Question 16

What does the following code output?
DecimalFormat percent = new DecimalFormat("0.00%");
System.out.println(percent.format(0.308));
(a)3.080%
(b)30.80%
(c))0308%
(d)308.0%

Question 17

What does the following code output?
DecimalFormat dfQuestion = new DecimalFormat("#0.##E0");
System.out.println(dfQuestion.format(12.7896987));
(a)12.79E0
(b)12.8E0
(c)1.28E1
(d))13E2

Question 18

The new line character is represented as '\n'.

Question 19

The printf method can be used to output multiple formatted values.

Question 20

Write ONE Java statement to display your first and last name on two separate lines.

Question 21

What does it mean to prompt the user?

Question 22

Write a Java statement to create and initialize a Scanner object named input.

Question 23

What do the format specifiers d,f,e,g,s and c represent?

Question 24

Write a Java program to create and display 57.32% using the DecimalFormat class.Include the necessary import statement to use the DecimalFormat class.

Question 25

If there is no loss of efficiency in importing an entire Java package instead of importing only classes you use into your program,why would you not just import the entire package?

Question 26

Write a complete Java console application that prompts the user for two numbers,multiplies the numbers,and then displays the result to the user.

Question 27

Why is echoing user input a good programming practice?

Question 28

What is whitespace and why is it import when reading input from the keyboard using the Scanner class?

Question 29

Explain the significance of the pattern string used by the DecimalFormat object,and give an example of a valid pattern.