Deck 4: Defining Classes I

Question 1

In a method invocation,there must be exactly the same number of arguments in parentheses as there are formal parameters in the method definition heading.

Answer 1

True

Question 2

Two methods that are expected to be in all Java classes are:
(a)getName and setName
(b)toString and equals
(c)compareTo and charAt
(d)toLowerCase and toUpperCase

Answer 2

B

Question 3

The parameter this refers to
(a)instance variables
(b)local variables
(c)global variables
(d)the calling object

Answer 3

D

Question 4

A variable whose meaning is confined to an object of a class is called:
(a)instance variable
(b)local variable
(c)global variable
(d)none of the above

Question 5

An object of class A is an instance of class A.

Question 6

Accessor methods:
(a)return something equivalent to the value of an instance variable.
(b)promotes abstraction
(c)both A and B
(d)none of the above

Question 7

A variable whose meaning is confined to a method definition is called an/a
(a)instance variable
(b)local variable
(c)global variable
(d)none of the above

Question 8

The new operator:
(a)allocates memory
(b)is used to create an object of a class
(c)associates an object with a variable that names it.
(d)All of the above.

Question 9

The Java language supports global variables.

Question 10

A method that performs some action other than returning a value is called a __________ method.
(a)null
(b)void
(c)public
(d)private

Question 11

The body of a method that returns a value must contain at least one _________ statement.
(a)void
(b)invocation
(c)thows
(d)return

Question 12

A program whose only task is to test a method is called a:
(a)driver program
(b)stub
(c)bottom-up test
(d)recursive method

Question 13

In Java,call-by-value is only used with:
(a)objects
(b)primitive types
(c)this
(d)all of the above

Question 14

When you want the parameters in a method to be the same as the instance variables you can use the _____ parameter.
(a)String
(b)hidden
(c)default
(d)this

Question 15

An invocation of a method that returns a value can be used as an expression any place that a value of the Type_Returned can be used.

Question 16

Java has a way of officially hiding details of a class definition.To hide details,you mark them as _________.
(a)public
(b)protected
(c)private
(d)all of the above

Question 17

A _________ states what is assumed to be true when the method is called.
(a)prescript
(b)postscript
(c)precondition
(d)postcondition

Question 18

In Java,a block is delimited by:
(a)( )
(b)/* */
(c)" "
(d){ }

Question 19

A more eloquent approach in implementing mutator methods is to return a ________ value.
(a)int
(b)char
(c)boolean
(d)double

Question 20

A set method is:
(a)an accessor method
(b)a mutator method
(c)a recursive method
(d)none of the above

Question 21

Write a method called Greeting that displays a personalized greeting given a first name.

Question 22

Mutator methods can return integer values indicating if the change of the instance variable was a success.

Question 23

The modifier private means that an instance variable can be accessed by name outside of the class definition.

Question 24

Boolean expressions may be used to control if-else or while statements.

Question 25

Java supports operator overloading.

Question 26

Method overloading is when two or more methods of the same class have the same name but differ in number or types of parameters.

Question 27

It is considered good programming practice to validate a value passed to a mutator method before setting the instance variable.

Question 28

Only the default constructor has the this parameter.

Question 29

Discuss the public and private modifiers in context of methods and instance variables.

Question 30

Discuss the importance of accessor and mutator methods and how they apply to the abstraction concept.

Question 31

Define the terms arguments and parameters.How are they different?

Question 32

What is the purpose of the new operator?

Question 33

Write a Java method that prints the phrase "Five purple people eaters were seen munching Martians".

Question 34

Write a method called power the computes xⁿ where x and n and positive integers.The method has two integer parameters and returns a value of type long.

Question 35

Write a Java method that returns the value of PI,where PI = 3.1415926535.

Question 36

Discuss a situation in which it is appropriate to use the this parameter.

Question 37

Write a method called isEqual that returns a Boolean value.The method compares two integers for equality.

Question 38

When you give a command to run a Java program,the runtime system invokes the class constructor.

Question 39

Inside a Java method definition,you can use the keyword this as a name for the calling object.

Question 40

Create a class named Appointment that contains instance variables startTime,endTime,dayOfWeek (valid values are Sunday through Saturday),and a date which consists of a month,day and year.All times should be in military time,therefore it is appropriate to use integers to represent the time.Create the appropriate accessor and mutator methods.

Question 41

Write a driver program to test your Student class created in question #14.

Question 42

Add two constructors to the Appointment class created in question #9.Include a default constructor and a constructor to initialize an Appointment to suitable arguments.

Question 43

Write preconditions and postconditions for the power method you wrote in question #4.

Question 44

Write a Java class that represents a Student with instance variables name,id,and gpa.Include constructors,accessor,mutator and any facilitator methods you may need.