Deck 2: Data and Expressions

Question 1

Which of the following data types only allows one of two possible values to be assigned?

A) char
B) int
C) boolean
D) float
E) long

Answer 1

C
Explanation: Variables of type boolean can only be assigned values of true or false. The other four types can be assigned many different values.

Question 2

Which of the following lines allows a programmer to use the Scanner class in a Java program?

A) import java.util.Scanner;
B) using Scanner;
C) include Scanner;
D) include java.util.Scanner;
E) any of the above will allow the programmer to use the Scanner class

Answer 2

A
Explanation: The Scanner class must be imported using the import command before it may be used in a program.

Question 3

The byte type can be assigned a larger range of numbers than the int type.

Answer 3

False
Explanation: The int type can hold numbers in the range -2,147,483 to 2,147,483,647 while the byte type can only hold numbers in the range -128 to 127.

Question 4

Which of the following is an example of an invalid expression in Java?

A) result = a + b;
B) result = (14 + 9) * 5;
C) result = ((19 + 4) - 5;
D) result = firstNum % secondNum;
E) result = firstNum / secondNum % thirdNum;

Question 5

Consider the following snippet of code: int firstNum = 25;
Int seconNum = 3;
Double result = 25/3;
System.out.println(result);
What is output by this code?

A) 8.0
B) 8.333333333
C) 8
D) 8.3
E) This snippet of code will result in a compiler error

Question 6

Java has two basic kinds of numeric values: _____________, which have no fractional part, and ___________________ which do.

A) shorts, longs
B) doubles, floating points
C) characters, bytes
D) integers, floating points
E) integers, longs

Question 7

In order to make a variable a constant which modifier must be included in its declaration?

A) public
B) final
C) static
D) void
E) private

Question 8

In order for a string literal may span multiple lines in the program code.

Question 9

Information is most likely to be lost in what kind of data conversion?

A) A widening conversion
B) A narrowing conversion
C) promotion
D) assignment conversion
E) no information will be lost in any of the conversions listed above

Question 10

Which of the following is not an arithmetic operation in Java?

A) +
B) -
C) *
D) %
E) These are all arithmetic operations in Java

Question 11

Which of the following are examples of invalid string literals?

A) "Hello World!"
B) "4 score and 7 years ago, our forefathers brought forth..."
C) "z"
D) ""
E) none of the above

Question 12

Variables declared with the final modifier cannot have new values assigned to them.

Question 13

A(n) ________________ is a piece of data that we send to a method.

A) parameter
B) object
C) escape sequence
D) service
E) expression

Question 14

Java is a strongly-typed language.

Question 15

Consider the following snippet of code: System.out.println("30 plus 25 is " + 30 + 25);
What is printed by this line?

A) 30 plus 25 is 55
B) 30 plus 25 is 30
C) 30 plus 25 is 25
D) 30 plus 25 is 3025
E) this snippet of code will result in a compiler error

Question 16

Which of the following is an example of an invalid assignment or declaration statement?

A) int age = 30;
B) int money, dollars = 0, cents = 0;
C) int years = 1; months = 12; days = 365;
D) int length, meters, centimeters, millimeters;
E) none of the above

Question 17

Consider the expression: result = 12 + 5 / 2;
What value stored in result after this line is executed?

A) 14.5
B) 8.5
C) 9
D) 14
E) this will result in a compiler error

Question 18

Consider the expression: result = 15 % 4;
What value stored in result after this line is executed?

A) 0
B) 1
C) 2
D) 3
E) 4

Question 19

A _______________ is a list of characters in a particular order. Examples include ASCII and Unicode.

A) character literal
B) character set
C) char data type
D) control character
E) none of the above

Question 20

The print and the println methods are identical and can be used interchangeably.

Question 21

Write a single println statement that prints out the following line.
"There is Thingumbob shouting!" the Bellman said,

Question 22

The type of result produced by a mathematical expression depends on the types of the operands.

Question 23

Write a short program that allows the user to enter the year that they were born (as an integer) and outputs the age that they will be at the end of this year. Declare the current year as a constant.

Question 24

What are some reasons that you might want to declare a variable as final?

Question 25

Consider the following snippet of code:
int firstNum = 5;
int secondNum = firstNum++;
int thirdNum = 6*(++firstNum);
What values are stored in firstNum, secondNum and thirdNum after these lines are executed? Explain your answer.

Question 26

Promotion is a widening data conversion that is explicitly requested by the programmer.

Question 27

Java uses the ASCII character set to represent character data.

Question 28

The Scanner class must be imported using the import statement before it can be used in a program.

Question 29

Explain why it might not be safe for a programmer to use a narrowing conversion.

Question 30

Write a short application that converts inches to centimeters. It should read the number of inches from the user as a floating point number and output the number of inches and the number of centimeters at the end of the program. Note that there are 2.54 centimeters in an inch.

Question 31

Write a single line of Java code that computes the average of three integer variables - num1, num2, and num3 - and stores the result in a variable of type double called result.

Question 32

Write an application that prints out the following using a single call to the print method.
Hello!
How
are you?

Question 33

Write a short application that computes the perimeter of a rectangle. It should allow the user to input the length and width of the rectangle as a double.

Question 34

Write a short program that declares a single integer variable called age and assigns it a value equal to your age. Also have it print out your age using the age variable. The output of your program should look similar to the following:
I am 30 years old.

Question 35

Consider the following snippet of code.
int iResult;
float fResult;
int rResult;
int iNum1 = 25;
int iNum2 = 8;
iResult = iNum1/iNum2;
rResult = iNum2%iNum2;
fResult = (float) iNum1/iNum2;
What values are stored in iResult, rResult and fResult? Explain your answers.

Question 36

For the following expression, indicate the order that in which the operators will be evaluated.
a + b * c / (d -
e)

Question 37

In Java, all floating point literals are assumed to be of type float.

Question 38

How are primitive data types and object data types related?

Question 39

Explain the difference between the print and the println methods.

Question 40

Suppose your numeric grade is calculated using the following formula:
Test 1: 15%
Test 2: 15%
Final Exam: 30%
Homework: 10%
Programming Projects: 30%
Determine a good variable name to represent each of these values. Write a single expression to compute your grade assuming the variables have been declared and each one stores its value as an integer in the range 0 to 100.