Question 1

You must call most methods other than ________ explicitly to tell them to perform their tasks.

Accepted Answer

A) public methods 
B) main 
C) static methods 
D) private methods 
A) public methods 
B) main 
C) static methods 
D) private methods B

Question 2

Which of the following statements is false?

Accepted Answer

A) Each class declaration that begins with the access modifier private must be stored in a file that has the same name as the class and ends with the .java filename extension. 
B) Every class declaration contains keyword class followed immediately by the class's name. 
C) Class,method and variable names are identifiers. 
D) An object has attributes that are implemented as instance variables and carried with it throughout its lifetime. 
A) Each class declaration that begins with the access modifier private must be stored in a file that has the same name as the class and ends with the .java filename extension. 
B) Every class declaration contains keyword class followed immediately by the class's name. 
C) Class,method and variable names are identifiers. 
D) An object has attributes that are implemented as instance variables and carried with it throughout its lifetime. A

Question 3

Types in Java are divided into two categories.The primitive types are boolean,byte,char,short,int,long,float and double.All other types are ________ types.

Accepted Answer

A) static 
B) reference 
C) declared 
D) source 
A) static 
B) reference 
C) declared 
D) source B

Question 4

Which of the following statements is false?

Accepted Answer

A) In the UML,each class is modeled in a class diagram as a rectangle with three compartments.The top one contains the class's name centered horizontally in boldface.The middle one contains the class's attributes,which correspond to instance variables in Java.The bottom one contains the class's operations,which correspond to methods and constructors in Java. 
B) UML represents instance variables as an attribute name,followed by a colon and the type. 
C) Private attributes are preceded by the keyword private in the UML. 
D) The UML models operations by listing the operation name followed by a set of parentheses.A plus sign (+)in front of the operation name indicates that the operation is a public. 
A) In the UML,each class is modeled in a class diagram as a rectangle with three compartments.The top one contains the class's name centered horizontally in boldface.The middle one contains the class's attributes,which correspond to instance variables in Java.The bottom one contains the class's operations,which correspond to methods and constructors in Java. 
B) UML represents instance variables as an attribute name,followed by a colon and the type. 
C) Private attributes are preceded by the keyword private in the UML. 
D) The UML models operations by listing the operation name followed by a set of parentheses.A plus sign (+)in front of the operation name indicates that the operation is a public.

Question 5

The format specifier ________ is used to output values of type float or double.

Accepted Answer

A) %f 
B) %d 
C) %fd 
D) %r 
A) %f 
B) %d 
C) %fd 
D) %r

Question 6

Which of the following statements is false?

Accepted Answer

A) If a class does not define constructors,the compiler provides a default constructor with no parameters. 
B) If you declare a constructor for a class,the compiler will not create a default constructor for that class. 
C) The UML models constructors in the third compartment of a class diagram. 
D) To distinguish a constructor from a class's operations,the UML places the word "constructor" between double quotes before the constructor's name. 
A) If a class does not define constructors,the compiler provides a default constructor with no parameters. 
B) If you declare a constructor for a class,the compiler will not create a default constructor for that class. 
C) The UML models constructors in the third compartment of a class diagram. 
D) To distinguish a constructor from a class's operations,the UML places the word "constructor" between double quotes before the constructor's name.

Question 7

If a class does not define constructors,the compiler provides a default constructor with no parameters,and the class's instance variables are initialized to ________.

Accepted Answer

A) zero 
B) null 
C) their default values. 
D) false 
A) zero 
B) null 
C) their default values. 
D) false

Question 8

Each class you create becomes a new ________ that can be used to declare variables and create objects.

Accepted Answer

A) package 
B) instance 
C) library 
D) type. 
A) package 
B) instance 
C) library 
D) type.

Question 9

The format specifier %.2f specifies that two digits of precision should be output ________ in the floating-point number.

Accepted Answer

A) to the left of the decimal point 
B) centered 
C) to the right of the decimal point 
D) None of the above. 
A) to the left of the decimal point 
B) centered 
C) to the right of the decimal point 
D) None of the above.

Question 10

Floating-point literals are of type ________ by default.

Accepted Answer

A) float 
B) double 
C) real 
D) decimal 
A) float 
B) double 
C) real 
D) decimal

Question 11

Which of the following statements is false?

Accepted Answer

A) A floating-point number is a number with a decimal point. 
B) Java provides two primitive types for storing floating-point numbers in memory-float and double. 
C) Variables of type float represent single-precision floating-point numbers and have seven significant digits. 
D) Variables of type double represent double-precision floating-point numbers;these require twice as much memory as float variables and provide 14 significant digits. 
A) A floating-point number is a number with a decimal point. 
B) Java provides two primitive types for storing floating-point numbers in memory-float and double. 
C) Variables of type float represent single-precision floating-point numbers and have seven significant digits. 
D) Variables of type double represent double-precision floating-point numbers;these require twice as much memory as float variables and provide 14 significant digits.

Question 12

Which of the following statements is true?

Accepted Answer

A) Constructors can specify parameters and return types. 
B) Constructors can specify parameters but not return types. 
C) Constructors cannot specify parameters but can specify return types. 
D) Constructors can specify neither parameters nor return types. 
A) Constructors can specify parameters and return types. 
B) Constructors can specify parameters but not return types. 
C) Constructors cannot specify parameters but can specify return types. 
D) Constructors can specify neither parameters nor return types.

Question 13

A class that creates an object of another class,then calls the object's methods,is called a(n)________ class.

Accepted Answer

A) object-oriented 
B) inherited 
C) caller 
D) driver. 
A) object-oriented 
B) inherited 
C) caller 
D) driver.

Question 14

Which of the following statements is false?

Accepted Answer

A) You must create an object of class JOptionPane to use its static method showMessageDialog. 
B) JOptionPane method showInputDialog displays an input dialog containing a prompt and a field (known as a text field)in which a user can enter text. 
C) String method format works like method System.out.printf,except that format returns the formatted String rather than displaying it in a command window. 
D) An input dialog allows the user to enter data into a program. 
A) You must create an object of class JOptionPane to use its static method showMessageDialog. 
B) JOptionPane method showInputDialog displays an input dialog containing a prompt and a field (known as a text field)in which a user can enter text. 
C) String method format works like method System.out.printf,except that format returns the formatted String rather than displaying it in a command window. 
D) An input dialog allows the user to enter data into a program.

Question 15

Reference-type variables (called references)store ________ in memory.

Accepted Answer

A) the value of an object 
B) a copy of an object 
C) the location of an object 
D) the size of an object 
A) the value of an object 
B) a copy of an object 
C) the location of an object 
D) the size of an object

Question 16

Which of the following statements is false?

Accepted Answer

A) The method's return type specifies the type of data returned to a method's caller. 
B) Empty parentheses following a method name indicate that the method does not require any parameters to perform its task. 
C) When a method that specifies a return type other than void is called and completes its task,the method must return a result to its calling method 
D) Classes often provide public methods to allow the class's clients to set or get private instance variables;the names of these methods must begin with set or get. 
A) The method's return type specifies the type of data returned to a method's caller. 
B) Empty parentheses following a method name indicate that the method does not require any parameters to perform its task. 
C) When a method that specifies a return type other than void is called and completes its task,the method must return a result to its calling method 
D) Classes often provide public methods to allow the class's clients to set or get private instance variables;the names of these methods must begin with set or get.

Question 17

An import declaration is not required if you always refer to a class with its ________ name,which includes its package name and class name.

Accepted Answer

A) compile-time 
B) default package 
C) paired 
D) fully qualified name 
A) compile-time 
B) default package 
C) paired 
D) fully qualified name

Question 18

Which of the following statements is false?

Accepted Answer

A) Most classes you'll use in Java programs must be imported explicitly. 
B) There's a special relationship between classes that are compiled in the same directory.By default,such classes are considered to be in the same package-known as the default package. 
C) Classes in the same package are implicitly imported into main. 
D) An import declaration is not required when one class in a package uses another in the same package. 
A) Most classes you'll use in Java programs must be imported explicitly. 
B) There's a special relationship between classes that are compiled in the same directory.By default,such classes are considered to be in the same package-known as the default package. 
C) Classes in the same package are implicitly imported into main. 
D) An import declaration is not required when one class in a package uses another in the same package.

Question 19

Which of the following statements is true?

Accepted Answer

A) Local variables are automatically initialized. 
B) Every instance variable has a default initial value-a value provided by Java when you do not specify the instance variable's initial value. 
C) The default value for an instance variable of type String is void. 
D) The argument types in the method call must be identical to the types of the corresponding parameters in the method's declaration. 
A) Local variables are automatically initialized. 
B) Every instance variable has a default initial value-a value provided by Java when you do not specify the instance variable's initial value. 
C) The default value for an instance variable of type String is void. 
D) The argument types in the method call must be identical to the types of the corresponding parameters in the method's declaration.

Question 20

A key part of enabling the JVM to locate and call method main to begin the app's execution is the ________ keyword,which indicates that main can be called without first creating an object of the class in which the method is declared.

Accepted Answer

A) stable 
B) private 
C) static 
D) public 
A) stable 
B) private 
C) static 
D) public

Exam 3: Introduction to Classes and Objects

You must call most methods other than ________ explicitly to tell them to perform their tasks.

Which of the following statements is false?

Types in Java are divided into two categories.The primitive types are boolean,byte,char,short,int,long,float and double.All other types are ________ types.

Which of the following statements is false?

The format specifier ________ is used to output values of type float or double.

Which of the following statements is false?

If a class does not define constructors,the compiler provides a default constructor with no parameters,and the class's instance variables are initialized to ________.

Each class you create becomes a new ________ that can be used to declare variables and create objects.

The format specifier %.2f specifies that two digits of precision should be output ________ in the floating-point number.

Floating-point literals are of type ________ by default.

Which of the following statements is false?

Which of the following statements is true?

A class that creates an object of another class,then calls the object's methods,is called a(n)________ class.

Which of the following statements is false?

Reference-type variables (called references)store ________ in memory.

Which of the following statements is false?

An import declaration is not required if you always refer to a class with its ________ name,which includes its package name and class name.

Which of the following statements is false?

Which of the following statements is true?

A key part of enabling the JVM to locate and call method main to begin the app's execution is the ________ keyword,which indicates that main can be called without first creating an object of the class in which the method is declared.

Introduction to Computers and Java

Introduction to Java Applications

Control Statements: Part 1

Control Statements: Part 2

Methods: a Deeper Look

Arrays and Arraylists

Classes and Objects: a Deeper Look

Object Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism

Exception Handling

Gui Components: Part 1

Graphics and Java 2D

Strings

Files,streams and Object Serialization

Generic Collections

Lambdas

Recursion

Searching, Sorting and Big O

Generic Classes and Methods

Custom Generic Data Structures

Concurrency

Accessing Databases With Jdbc

JavaFX

Filters