Deck 5: Defining Classes Ii

Question 1

A copy constructor has _________ parameters.
(a)zero
(b)one
(c)two
(d)three

Answer 1

B

Question 2

All of these are methods of Java's Math class except:
(a)pow
(b)min
(c)random
(d)toString

Answer 2

D

Question 3

The program included in the Java SDK that allows a programmer to separate the class interface from the class implementation is called:
(a)javac
(b)java
(c)javadoc
(d)none of the above

Answer 3

C

Question 4

A class that contains public methods that can change the data in the object of a class is called a/an:
(a)mutable class
(b)immutable class
(c)invariant class
(d)none of the above

Question 5

The method trim of the String class trims off:
(a)Leading white space
(b)Trailing white space
(c)Leading and trailing white space
(d)Blanks

Question 6

To create a package,you must add a package statement at the ____________ of each class file.
(a)beginning
(b)end
(c)before each method signature
(d)after the import statements

Question 7

The Math method that returns the nearest whole number that is greater than or equal to its argument is:
(a)round
(b)ceil
(c)floor
(d)all of the above

Question 8

A main method can be placed inside a class definition.

Question 9

In a static method,you may use the this parameter either explicitly or implicitly.

Question 10

An example of secondary memory is:
(a)RAM
(b)ROM
(c)hard disk
(d)all of the above

Question 11

Static variables are often used:
(a)in arithmetic expressions
(b)to communicate between objects
(c)within looping structures
(d)all of the above

Question 12

A condition that allows a programmer to circumvent the private modifier and change the private instance variable is called:
(a)a copy constructor
(b)a privacy leak
(c)a class invariant
(d)an anonymous object

Question 13

Javadoc requires a comment to be delimited by _________ to be included in the extracted class interface.
(a)// //
(b)/* */
(c)/** */
(d)" "

Question 14

The conversion from an object of a wrapper class to a value of its associated primitive type is called:
(a)Boxing
(b)Unboxing
(c)Converting
(d)Reinstantiating

Question 15

null can be used:
(a)to indicate a variable has no real value
(b)in a Boolean expression with ==
(c)as a placeholder
(d)all of the above

Question 16

When you use the assignment operator with variables of a class type,you are assigning a:
(a)value
(b)primitive type
(c)local variable
(d)reference

Question 17

A static method is one that can be used with a _____________.
(a)instance variable
(b)local variable
(c)global variable
(d)the class name as a calling object

Question 18

Converting from a value of primitive type to a corresponding object of its associated wrapper class is called:
(a)Boxing
(b)Unboxing
(c)Converting
(d)Reinstantiating

Question 19

All of the following are wrapper classes except:
(a)String
(b)Integer
(c)Character
(d)Double

Question 20

Only ______ copy/copies of a static variable are available to objects of a class.
(a)one
(b)two
(c)three
(d)none of the above

Question 21

Write a Java method that returns true if and only if a character is a digit or a letter.The method should display appropriate feedback to the console.

Question 22

Primitive types are reference types.

Question 23

Write ONE Java statement that computes and displays a random number between 1 and 25.

Question 24

Write a statement that creates and initializes a static variable named salesTax to 7.59.

Question 25

Deprecated methods should be used in new Java code.

Question 26

You should avoid the use of null as an argument to a method.

Question 27

Write a statement that creates a constant variable named TAX_RATE.The tax rate is 8.25%.

Question 28

A class invariant is a statement that is always true for every object of the class.

Question 29

How many bytes are contained within 16-bits,32-bits,64-bits?

Question 30

Wrapper classes provide a class type corresponding to each of the primitive types so that you can have class types that behave somewhat like primitive types.

Question 31

Explain in detail how main memory works.

Question 32

You may use methods of the Math class without an import statement.

Question 33

Wrapper classes are provided for all primitive Java types except Boolean.

Question 34

To use a package,the program must contain an import statement that names the package.

Question 35

A bit may have the value of either a 1 or 0.

Question 36

Write ONE Java statement that computes and displays the value of 2⁵.

Question 37

When used with objects,what is the equality ( == )operator really comparing?

Question 38

The String class is a mutable class.

Question 39

Define boxing and unboxing.

Question 40

All versions of Java support automatic boxing.

Question 41

Does an object created with a copy constructor reference the same memory location that the original object references? Explain.

Question 42

Add accessor and mutator methods to the Book class created in question #13.

Question 43

Explain how a package is named in Java.

Question 44

Create a Java class named Book with instance variables title,author,ISBN,and yearPublished.Include javadoc style comments to describe your interface.Such a class would normally have methods,but you are not required to supply any methods.

Question 45

Add a constructor and a copy constructor to the Book class created in question #13.

Question 46

What is the purpose of Java's wrapper classes?