Question 1

What is the correct way to invoke methods on variables in Java that are strings?

Accepted Answer

A) Methods can only be invoked on string constants, not on variables. 
B) For each method there is a special operator that must be used. 
C) There are no methods available in Java for string variables. 
D) Invoke them using the variable name and the dot (.) notation. 
A) Methods can only be invoked on string constants, not on variables. 
B) For each method there is a special operator that must be used. 
C) There are no methods available in Java for string variables. 
D) Invoke them using the variable name and the dot (.) notation. D

Question 2

What is wrong with the following code snippet?

Accepted Answer

A) The code snippet uses a variable that has not yet been initialized. 
B) The code snippet uses a variable that has not been declared. 
C) The code snippet attempts to assign a decimal value to an integer variable. 
D) The code snippet attempts to assign an integer value to a decimal variable. 
A) The code snippet uses a variable that has not yet been initialized. 
B) The code snippet uses a variable that has not been declared. 
C) The code snippet attempts to assign a decimal value to an integer variable. 
D) The code snippet attempts to assign an integer value to a decimal variable. C

Question 3

What will be printed by the statement below?
System.out.print("O"my	\"no!");

Accepted Answer

A) O"myt"no! 
B) O"my	\"no! 
C) O\ my	\\ no! 
D) O"my "no! 
A) O"myt"no! 
B) O"my	\"no! 
C) O\ my	\\ no! 
D) O"my "no! D

Question 4

When you purchase donuts, they come in boxes of 12, so 24 donuts take 2 boxes.All donuts need to be in a box, so if you buy 13 donuts, you'll get 2 boxes with 12 in the first box and 1 in the second.If the integer variable numberOfDonuts contains the positive number of donuts purchased, which of the following will correctly give the number of boxes needed?

Accepted Answer

A) int numberOfBoxes = (numberOfDonuts + 11) / 12; 
B) int numberOfBoxes = numberOfDonuts / 12; 
C) int numberOfBoxes = 1 + numberOfDonuts / 12; 
D) int numberOfBoxes = numberOfDonuts / 12 + numberOfDonuts % 12; 
A) int numberOfBoxes = (numberOfDonuts + 11) / 12; 
B) int numberOfBoxes = numberOfDonuts / 12; 
C) int numberOfBoxes = 1 + numberOfDonuts / 12; 
D) int numberOfBoxes = numberOfDonuts / 12 + numberOfDonuts % 12;

Question 5

Which statement is true about variable names in Java?

Accepted Answer

A) They can contain the percent sign (%) 
B) They can contain an underscore symbol ("_") 
C) They can contain spaces 
D) They must make sense as a word 
A) They can contain the percent sign (%) 
B) They can contain an underscore symbol ("_") 
C) They can contain spaces 
D) They must make sense as a word

Question 6

What is the value of Math.abs(-2)?

Accepted Answer

A) -2 
B) 0 
C) 2 
D) 4 
A) -2 
B) 0 
C) 2 
D) 4

Question 7

Assume the following variable has been declared and given values as shown:
String name = "Mamey, Jean";
Which statement will print the name as "Jean Mamey"?

Accepted Answer

A) System.out.print(name.substring(7) + " " + name.substring(0, 5)); 
B) System.out.print(name.substring(8, 4) + " " + name.substring(1, 5)); 
C) System.out.print(name.substring(8) + " " + name.substring(1, 4)); 
D) System.out.print(name.substring(2) + " " + name.substring(1)); 
A) System.out.print(name.substring(7) + " " + name.substring(0, 5)); 
B) System.out.print(name.substring(8, 4) + " " + name.substring(1, 5)); 
C) System.out.print(name.substring(8) + " " + name.substring(1, 4)); 
D) System.out.print(name.substring(2) + " " + name.substring(1));

Question 8

Which of the following options declares a float variable?

Accepted Answer

A) Float age; 
B) flt age; 
C) float age; 
D) age: float; 
A) Float age; 
B) flt age; 
C) float age; 
D) age: float;

Question 9

Which is the Java equivalent of the following mathematical expression?

Accepted Answer

A) c = (Math.sqrt(a) + Math.sqrt(b)) * 2; 
B) c = Math.sqrt(a * 2) + Math.sqrt(b * 2); 
C) c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2)); 
D) c = Math.pow((Math.sqrt(a) + Math.sqrt(b)), 2); 
A) c = (Math.sqrt(a) + Math.sqrt(b)) * 2; 
B) c = Math.sqrt(a * 2) + Math.sqrt(b * 2); 
C) c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2)); 
D) c = Math.pow((Math.sqrt(a) + Math.sqrt(b)), 2);

Question 10

Assume the following variables have been declared as shown and given values elsewhere:
double a, b, c;
The discriminant of a quadratic equation is defined to be:   Which of the following statements will assign the correct value to discriminant?

Accepted Answer

A) double discriminant = Math.sqrt(b * b - 4 * a * c); 
B) double discriminant = Math.sqrt(b * b) - 4 * a * c; 
C) double discriminant = Math.sqrt(b * b) - Math.sqrt(4 * a * c); 
D) double discriminant = Math.sqrt(b2 - 4ac) 
A) double discriminant = Math.sqrt(b * b - 4 * a * c); 
B) double discriminant = Math.sqrt(b * b) - 4 * a * c; 
C) double discriminant = Math.sqrt(b * b) - Math.sqrt(4 * a * c); 
D) double discriminant = Math.sqrt(b2 - 4ac)

Question 11

Which is the Java equivalent of the following mathematical expression?

Accepted Answer

A) c = Math.sqrt(a * 2 + b * 2); 
B) c = Math.sqrt(a * 2) + Math.sqrt(b * 2); 
C) c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2)); 
D) c = Math.sqrt(Math.pow(a, 2)) + Math.sqrt(Math.pow(b, 2)); 
A) c = Math.sqrt(a * 2 + b * 2); 
B) c = Math.sqrt(a * 2) + Math.sqrt(b * 2); 
C) c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2)); 
D) c = Math.sqrt(Math.pow(a, 2)) + Math.sqrt(Math.pow(b, 2));

Question 12

What is the output of the following code snippet?

Accepted Answer

A) 25.0 
B) 34 
C) 7.0 
D) 14 
A) 25.0 
B) 34 
C) 7.0 
D) 14

Question 13

What is the output of the following statement sequence?

Accepted Answer

A) 4 
B) Compile-time error 
C) Run-time error 
D) 16 
A) 4 
B) Compile-time error 
C) Run-time error 
D) 16

Question 14

What is the result of the following statement?
String s = "You" + "had" + "me" + "at" + "hello";

Accepted Answer

A) The string s has the following value: "You had me at "hello" 
B) The statement results in an error because the + operator can be used only with numbers 
C) The statement results in an error because the + operation cannot be performed on string literals 
D) The string s has the following value: "Youhadmeathello" 
A) The string s has the following value: "You had me at "hello" 
B) The statement results in an error because the + operator can be used only with numbers 
C) The statement results in an error because the + operation cannot be performed on string literals 
D) The string s has the following value: "Youhadmeathello"

Question 15

Assume the following variables have been declared and given values as shown:
int i = 2345;
double m = 67.8;
What will be printed by the statement below?
System.out.printf("Values are %10d and %7.2f", i, j);

Accepted Answer

A) Values are 2345 and 67.8 
B) Values are 2345 and 67.80 
C) Values are %10d and %7.2f 2345 67.8 
D) Values are %10d and %7.2f i j 
A) Values are 2345 and 67.8 
B) Values are 2345 and 67.80 
C) Values are %10d and %7.2f 2345 67.8 
D) Values are %10d and %7.2f i j

Question 16

How do you compute the length of the string str?

Accepted Answer

A) length(str) 
B) length.str 
C) str.length 
D) str.length() 
A) length(str) 
B) length.str 
C) str.length 
D) str.length()

Question 17

At what point in the problem-solving process should one write pseudocode?

Accepted Answer

A) After writing Java code, as a way to summarize the code's algorithm 
B) Before writing Java code, as a guide for a general solution 
C) After defining Java variables so that the pseudocode and data types make sense 
D) Before working out examples by hand in order to guide those examples 
A) After writing Java code, as a way to summarize the code's algorithm 
B) Before writing Java code, as a guide for a general solution 
C) After defining Java variables so that the pseudocode and data types make sense 
D) Before working out examples by hand in order to guide those examples

Question 18

One way to avoid round-off errors is to use:

Accepted Answer

A) Math.sqrt() 
B) Math.pow() 
C) Math.round() 
D) Math.truncate() 
A) Math.sqrt() 
B) Math.pow() 
C) Math.round() 
D) Math.truncate()

Question 19

Which of the methods below are static methods?
I.length
II.substring
III.pow
IV.sqrt

Accepted Answer

A) All the methods are static 
B) Only I, II and III 
C) Only II and IV 
D) Only III and IV 
A) All the methods are static 
B) Only I, II and III 
C) Only II and IV 
D) Only III and IV

Question 20

Assuming that the user inputs "Joe" at the prompt, what is the output of the following code snippet?

Accepted Answer

A) The code snippet does not compile because the += operator cannot be used in this context. 
B) Joe, Good morning 
C) , Good morning 
D) Joe 
A) The code snippet does not compile because the += operator cannot be used in this context. 
B) Joe, Good morning 
C) , Good morning 
D) Joe

Exam 4: Fundamental Data Types

What is the correct way to invoke methods on variables in Java that are strings?

What is wrong with the following code snippet?

What will be printed by the statement below? System.out.print("O\"my\t\\\"no!");

Which statement is true about variable names in Java?

What is the value of Math.abs(-2)?

Assume the following variable has been declared and given values as shown: String name = "Mamey, Jean"; Which statement will print the name as "Jean Mamey"?

Which of the following options declares a float variable?

Which is the Java equivalent of the following mathematical expression?

Assume the following variables have been declared as shown and given values elsewhere: double a, b, c; The discriminant of a quadratic equation is defined to be: Which of the following statements will assign the correct value to discriminant?

Which is the Java equivalent of the following mathematical expression?

What is the output of the following code snippet?

What is the output of the following statement sequence?

What is the result of the following statement? String s = "You" + "had" + "me" + "at" + "hello";

Assume the following variables have been declared and given values as shown: int i = 2345; double m = 67.8; What will be printed by the statement below? System.out.printf("Values are %10d and %7.2f", i, j);

How do you compute the length of the string str?

At what point in the problem-solving process should one write pseudocode?

One way to avoid round-off errors is to use:

Which of the methods below are static methods? I.length II.substring III.pow IV.sqrt

Assuming that the user inputs "Joe" at the prompt, what is the output of the following code snippet?

Introduction

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Object-Oriented Design

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The Java Collections Framework

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