Deck 3: Using Methods Classes and Objects

Question 1

____ is a principle of object-oriented programming that describes the encapsulation of method details within a class.

A) An interface
B) A calling method
C) Implementation hiding
D) Instantiation

Answer 1

C

Question 2

Application classes frequently instantiate objects that use the objects of other classes.

Answer 2

True

Question 3

Parentheses in a method declaration contain parameters that are "dropped into" the method.

Answer 3

True

Question 4

The arguments in a method call are often referred to as ____.

A) constants
B) concept parameters
C) actual parameters
D) argument lists

Question 5

You can write your own constructor methods; but when you don't write a constructor method for a class object, Java writes one for you.

Question 6

A method body provides information about how other methods can interact with it.

Question 7

A method header is also called a(n) _____.

A) argument
B) address
C) statement
D) declaration

Question 8

A method's identifier must be more than one word, must have embedded spaces, and can be a Java keyword.

Question 9

Any class can contain an unlimited number of methods.

Question 10

An application's main() method must have a void return type.

Question 11

A(n) ____ causes a value to be sent from a called method back to the calling method.

A) return statement
B) method statement
C) instantiation
D) inheritance relationship

Question 12

The ____ method executes first in an application, regardless of where you physically place it within its class.

A) start()
B) run()
C) main()
D) execute()

Question 13

When a value is returned from a method, you are required to use the value when the method is called.

Question 14

A(n) ____ is a program module that contains a series of statements that carry out a task.

A) argument
B) method
C) application
D) declaration

Question 15

A(n) ____ variable is known only within the boundaries of the method.

A) method
B) local
C) double
D) instance

Question 16

When a variable ceases to exist at the end of a method, programmers say the variable ____.

A) is undeclared
B) is out of memory range
C) goes out of scope
D) is lost

Question 17

You can identify a class that is an application because it contains a public static void main() method.

Question 18

The interface is the part of a method that the method's client does not see.

Question 19

Every object is a _____ of a more general class.

A) constant
B) member
C) method
D) field

Question 20

Data items you use in a call to a method are called ____.

A) arguments
B) instance variables
C) method declarations
D) headers

Question 21

The name of the ____ is always the same as the name of the class whose objects it constructs.

A) method
B) constructor
C) argument
D) variable

Question 22

A unique identifier is most likely used as a ____ key in a database.

A) special
B) public
C) static
D) primary

Question 23

A(n) ____ constructor is one that requires no arguments.

A) class
B) default
C) explicit
D) write

Question 24

Public classes are accessible by all objects, which means that public classes can be ____, or used as a basis for any other class.

A) saved
B) extended
C) copied
D) used

Question 25

Normally, you declare constructors to be ____________________ so that other classes can instantiate objects that belong to the class.

Question 26

Often, programmers list the ____________________ first because it is the first method used when an object is created.

Question 27

Access specifiers are sometimes called access ____________________.

Question 28

In order to allocate the needed memory for an object, you must use the ____ operator.

A) new
B) main
C) type
D) return

Question 29

A(n) ____________________ data type is a type whose implementation is hidden and accessed through its public methods.

Question 30

Method names that begin with ____ and set are very typical.

A) next
B) call
C) read
D) get

Question 31

For ease in locating class methods, many programmers store them in ____ order.

A) chronological
B) type
C) alphabetical
D) numeric

Question 32

When an application is run, the method that must be executed first must be named ____.

A) first()
B) void()
C) main()
D) final()

Question 33

A(n) ____ method is a method that creates and initializes class objects.

A) constructor
B) accessor
C) non-static
D) instance

Question 34

After an object has been instantiated, its methods can be accessed using the object's _____, a dot, and a method call.

A) identifier
B) class
C) operator
D) output

Question 35

Assigning ____ to a field means that no other classes can access the field's values.

A) user rights
B) protected access
C) key access
D) private access

Question 36

Methods used with object instantiations are called ____ methods.

A) accessor
B) internal
C) static
D) instance

Question 37

To execute a method, you ____________________ it from another method.

Question 38

Which of the following is NOT an initial value assigned to an object's data field by a default constructor?

A) numeric fields set to 0
B) Boolean fields set to true
C) character fields set to Unicode '\u0000'
D) a field of object references set to null

Question 39

____ parameters are variables in a method declaration that accept the values from the actual parameters.

A) System
B) Formal
C) Public
D) Static

Question 40

Methods that retrieve values are called ____ methods.

A) static
B) accessor
C) class
D) mutator

Question 42

A major advantage of a method is that it is easily reusable. What does it mean to reuse a method and what are the advantages of doing so?

Question 43

What are the two parts of every method? Describe them.

Question 44

Does a programmer need to write every class he or she uses? Why or why not?

Question 45

What are the four components of a method header?

Question 46

Write a valid class header with public access. Assign a valid identifier of your choice. Then write the body of the class that contains one data field named myPractice with a data type of double . Be sure to include any necessary curly braces and semicolons.

Question 47

How do you use a value returned from a method? Provide an example.

Question 48

Identify and describe the four components that make up the method header above.

Question 49

public Employee()
{
empSalary = 300.00;
}
The above code shows the Employee class constructor. What is a constructor and how would this default constructor operate?

Question 50

Explain the purpose of a return type of a method. Describe the return value of a method that returns no data.

Question 51

How do you create an object that is an instance of a class? Provide an example.

Question 52

What is a method and how is one used?

Question 53

How does the order in which methods appear in a class affect how the application executes? Please explain.

Question 54

public static void predictRaise(double salary)
{
double newSalary;
final double RAISE_RATE = 1.10;
newSalary = salary * RAISE_RATE;
System.out.println("Current salary: " +
salary + " After raise: " +
newSalary);
}
In the above code, what are the parameter data type and parameter identifier? How do you identify each?

Question 55

When creating a method that requires multiple parameters, why would a programmer need to understand a method's signature, and why must a method call match the called method's signature?

Question 56

What are the possible results if arguments to a method are passed in the wrong order?

Question 57

Describe instantiation and how it relates to 'is-a relationships.'

Question 58

Describe how you can use multiple arguments in a method. Provide an example.

Question 59

Describe what a public access class is and when you would use one. 

Question 60

What is the difference between a mutator method and an accessor method? Provide an example of each.

Question 61

public int getStudentNum()
{
return studentNum;
}
In the above code, identify if the method is a mutator method or an accessor method. Describe how the two types of methods differ and how they are similar.

Question 62

In the above code, the calculateBonus() method acts as a "black box." What does this mean?

Question 63

Fill in the blank line in the above code to add a statement that calls a method named practiceWithCalls that passes a parameter named testing of type double.

Question 64

public class Employee
{
private int empNum;
private double empSalary;
public void setEmpNum(int emp)
{
empNum = emp;
} 
public void setEmpSalary(double sal)
{
empSalary = sal;
}
}
Given the class defined in the code above, write the Java statements that will create a new employee instance called employee15 and assign an empNum of 15 and empSalary of 500.00 to that employee instance.

Question 65

Describe fully qualified identifiers and explain why they are necessary.

Question 66

In the above code, what would happen if the arguments passed to the method were passed in the wrong order?