Question 1

Consider the following method comment and method header:  Fill in the blank.

Accepted Answer

The answer of Consider the following method comment and method...

Question 2

We want to change the BankAccount class so that all accounts will have a monthly fee.The instance variable monthlyFee will hold the monthly fee.Which of the following constructors properly sets the monthly fee to a default value of 20?

Accepted Answer

Option A properly sets the monthlyFee instance variable to a default value of 20 by including it in the constructor and assigning it directly. Option B assigns the value of 20 to a local variable, which means it cannot be accessed outside of the constructor. Option C subtracts 20 from the initialBalance and assigns it to monthlyFee, which does not make sense as the monthly fee should be a fixed value. Option D subtracts 20 from the initialBalance, but does not set a value for monthlyFee. Therefore, option A is the best choice.

Question 3

We want to create a class that represents a geometric sequence.A geometric sequence is a sequence of numbers that begin at some value and then multiplies each value by some constant to get the next value.For example, the geometric sequence 1, 2, 4, 8, 16 starts at 1 and multiplies each term by 2 to get the next.The geometric sequence 10.8, 5.4, 2.7, 1.35 starts at 10.8 and multiplies each term by 0.5 to get the next.The basic framework of a geometric sequence class is below:  Which of the constructor specifications below will allow this code to behave as desired?

Accepted Answer

The constructor should have the same name as the class and not have any return type specified. Therefore, options A and C are not valid. Option B appears to be returning an object of type GeometricSequence, but it should be a constructor that initializes the object. Option D is the correct choice as it follows the correct naming convention for a constructor and accepts the necessary parameters to initialize an object of the GeometricSequence class.

Question 4

What is the name of the utility that formats comments into a set of documents that you can view in a Web browser?

Accepted Answer

Javadoc is a documentation generation utility in Java that parses comments in source code and produces an HTML documentation that can be viewed in a web browser. It helps in keeping the code organized and making it easier to understand for other developers. Option B) javac is a Java compiler, option C) javad is not a valid Java utility and option D) java is the command used to run Java programs.

Question 5

What are the operations that any programmer can use to create and manipulate objects of the class called?

Accepted Answer

The operations that any programmer can use to create and manipulate objects of a class are specified in its public interface. The public interface includes all the public methods and properties that can be accessed by external code. The implementation details, which include private methods and properties, are hidden from external code for security and maintainability purposes. Therefore, A, C, and D are incorrect options.

Question 6

The javadoc utility is used to

Accepted Answer

The javadoc utility is used to automatically generate HTML pages that describe classes. It processes special comments beginning with /** to generate API documentation in HTML format.

Question 7

Consider the following code to declare a constructor for the Player class:  Which statement is true?

Accepted Answer

There are no syntax errors in the code and a valid constructor for the Player class is defined, which means the code will compile successfully and result in the instantiation of a Player object when called.

Question 8

Which of the following corresponds to the getArea method header for a Square class assuming an integer value for a side length?

Accepted Answer

The getArea method should return an int value, and the method header should include parentheses to indicate that it is a method. Therefore, choice C is the correct option. The other choices are incorrect because they either do not include parentheses or use the incorrect data type.

Question 9

What is the name of the constructor for the BankAccount class?

Accepted Answer

The constructor for the BankAccount class is usually named the same as the class itself, in this case "BankAccount".

Question 10

We want to create a class that represents a geometric sequence.A geometric sequence is a sequence of numbers that begin at some value and then multiplies each value by some constant to get the next value.For example, the geometric sequence 1, 2, 4, 8, 16 starts at 1 and multiplies each term by 2 to get the next.The geometric sequence 10.8, 5.4, 2.7, 1.35 starts at 10.8 and multiplies each term by 0.5 to get the next.The basic framework of a geometric sequence class is below:

Accepted Answer

The best choice would be D, as a geometric sequence typically involves multiplying each term by some constant to get the next term, which would result in a double value. Therefore, the method should return a double value as well.

Question 11

Consider the following method comment and method header:  Fill in the blank.

Accepted Answer

The answer of Consider the following method comment and method...

Question 12

We want to change the BankAccount class so that all accounts will have a monthly fee.Which of the following will properly define the instance variable monthlyFee that holds the monthly fee?

Accepted Answer

The best choice is C because it declares the instance variable as private and of type double, which is necessary for holding the monthly fee as a decimal value. It also follows proper naming conventions for variables in Java. Option A is not technically incorrect, but it is missing the access modifier and could potentially be accessed from outside the class. Option B is not valid syntax in Java. Option D is not a valid syntax in Java and does not properly declare the variable type.

Question 13

Which special delimeter is used with the javadoc utility to document method arguments?

Accepted Answer

The special delimeter used with the javadoc utility to document method arguments is "@param". This allows the developer to provide a description of each method parameter in the Java code, which will then be included in the generated Javadoc documentation.

Question 14

.Consider the following method comment and method header:  Fill in the blank.

Accepted Answer

The "@" symbol is used to indicate a tag in a method comment, and the correct tag for describing a parameter is "@param". Therefore, option A is the best choice for completing the blank.

Question 15

Why is it a good idea for a programmer to write comments about a method first, before implementing it?

Accepted Answer

Writing comments about a method before implementing it forces the programmer to think through the steps they will take to accomplish the task. This helps ensure that they have a thorough understanding of the requirements and the best way to approach the task.

Question 16

We want to create a class that represents a geometric sequence.A geometric sequence is a sequence of numbers that begin at some value and then multiplies each value by some constant to get the next value.For example, the geometric sequence 1, 2, 4, 8, 16 starts at 1 and multiplies each term by 2 to get the next.The geometric sequence 10.8, 5.4, 2.7, 1.35 starts at 10.8 and multiplies each term by 0.5 to get the next.The basic framework of a geometric sequence class is below: public class Geometricsequence
{
private double currentValue;
private double multiplier;
}
Assume that the parameters to the constructor are initial and mult. What should the body of the constructor be?

Accepted Answer

In the constructor, we want to set the initial value for currentValue and multiplier. Therefore, we assign the parameter initial to currentValue and the parameter mult to multiplier.

Question 17

We want to change the BankAccount class so that all accounts will have a monthly fee.The instance variable monthlyFee will hold the monthly fee.Which of the following is the correct public interface for a constructor that sets both the initial balance and monthly fee?

Accepted Answer

Since monthlyFee is represented by a double, it should be included as a parameter in the constructor, and the correct syntax for including a double as a parameter is to include the keyword "double" before the parameter name, as in the example shown in choice B.

Question 18

What is the purpose of a clean and concise design for an object's public interface?

Accepted Answer

A clean and concise design for an object's public interface allows programmers to use the object without needing to know the details of the class implementation. This promotes encapsulation and separation of concerns, making it easier to modify and maintain code over time. It also promotes code reuse and supports more effective collaboration among team members.

Question 19

We want to change the BankAccount class so that all accounts will have a monthly fee.The instance variable monthlyFee will hold the monthly fee.Which of the following methods deducts the value of the monthly fee from the account?

Accepted Answer

Choice A correctly deducts the value of the monthly fee from the account by subtracting the value of monthlyFee from the current balance. Choices B and D are incorrect because they refer to an initialBalance variable which may not exist or may not accurately reflect the current balance of the account. Choice C sets the balance to be equal to the monthly fee, which does not deduct the fee from the account.

Question 20

The public constructors and methods of a class form the public _____ of the class.

Accepted Answer

The public constructors and methods of a class define the ways in which other code can interact with and use the class, forming the public interface. Initialization refers to the process of setting up an object's initial state. Implementation refers to the internal workings of the class, which are not necessarily visible or relevant to external code. Encapsulation refers to the practice of hiding implementation details from external code by using access modifiers to control visibility.

Quiz 3: Implementing Classes

Consider the following method comment and method header: Fill in the blank.