Java CH 6

Instance methods do not have the key word static in their headers.

T

Which of the following are classes from the Java API?

a. Scanner b. Random c. PrintWriter

It is common practice in object-oriented programming to make all of a class's

fields private

A constructor:

has the same name as the class

Quite often you have to use this statement to make a group of classes available to a program

import

When an object is created, the attributes associated with the object are called:

instance fields

The following package is automatically imported into all Java programs.

java.lang

A UML diagram does not contain:

object names

Most programming languages that are in use today are:

object-oriented

This is a group of related classes.

package

When you are working with a ____________, you are using a storage location that holds a piece of data.

primitive variable

The scope of a private instance field is:

the instance methods of the same class

When an object is passed as an argument to a method, what is passed into the method's parameter variable?

the object's memory address

Two or more methods in a class may have the same name as long as:

they have different parameter lists

In UML diagrams, this symbol indicates that a member is public.

+

In UML diagrams, this symbol indicates that a member is private:

-

What is stored by a reference variable?

A memory address

The java.lang package is automatically imported into all Java programs.

T

Instance methods do not have this key word in their headers:

static

This refers to the combining of data and code into a single object.

Encapsulation

Instance methods should be declared static.

F

A method that gets a value from a class's field but does not change it is known as a mutator method.

F

The public access specifier for a field indicates that the attribute may not be accessed by statements outside the class.

F

When a local variable in an instance method has the same name as an instance field, the instance field hides the local variable.

F

After the header, the body of the method appears inside a set of:

braces, {}

One or more objects may be created from a(n):

class

A class specifies the ________ and ________ that a particular type of object has.

fields; methods

A constructor is a method that:

performs initialization or setup operations.

The scope of a public instance field is:

the instance methods and methods outside the class

In a UML diagram to indicate the data type of a variable enter:

the variable name followed by a colon and the data type

In your textbook the general layout of a UML diagram is a box that is divided into three sections. The top section has the _______; the middle section holds _______; the bottom section holds _______.

class name; attributes or fields; methods

Which of the following statements will create a reference, str, to the string, "Hello, world"? String str = new String("Hello, world"); String str = "Hello, world";

1 and 2

Given the following code, what will be the value of finalAmount when it is displayed? public class Order { private int orderNum; private double orderAmount; private double orderDiscount; public Order(int orderNumber, double orderAmt, { double orderDisc) { orderNum = orderNumber; orderAmount = orderAmt; orderDiscount = orderDisc; } public double finalOrderTotal() { return orderAmount - orderAmount * orderDiscount; } } public class CustomerOrder { public static void main(String[] args) { Order order; int orderNumber = 1234; double orderAmt = 580.00; double orderDisc = .1; order = new Order(orderNumber, orderAmt, orderDisc); double finalAmount = order.finalOrderTotal(); System.out.println("Final order amount = $" + } } finalAmount); } }

522.00

The term "default constructor" is applied to the first constructor written by the author of a class.

F

Java allows you to create objects of this class in the same way you would create primitive variables.

String

Which of the following statements will create a reference, str, to the String, "Hello, World"?

String str = "Hello, World";

A class in not an object, but a description of an object.

T

A constructor is a method that is automatically called when an object is created.

T

A method that stores a value in a class's field or in some other way changes the value of a field is known as a mutator method.

T

An access specifier indicates how the class may be accessed.

T

An object can store data.

T

Shadowing is the term used to describe where the field name is hidden by the name of a local or parameter variable.

T

The term "no-arg constructor" is applied to any constructor that does not accept arguments.

T

Which of the following is not involved in finding the classes when developing an object-oriented application?

Write the code.

Look at the following statement. import java.util.*; This is an example of:

a wildcard import

Look at the following statement. import java.util.Scanner; This is an example of

an explicit import

A class's responsibilities include:

both A and B

In the cookie cutter metaphor, think of the ________ as a cookie cutter and ________ as the cookies.

class; objects

Overloading means multiple methods in the same class

have the same name, but different parameter lists

You should not define a class field that is dependent upon the values of other class fields:

in order to avoid having stale data

Another term for an object of a class is

instance

Methods that operate on an object's fields are called:

instance methods

Class objects normally have __________ that perform useful operations on their data, but primitive variables do not.

methods

What does the following UML diagram entry mean? + setHeight(h : double) : void

this is a public method with a parameter of data type double and does not return a value

Data hiding, which means that critical data stored inside the object is protected from code outside the object, is accomplished in Java by:

using the private access specifier on the class fields

For the following code, which statement is not true? public class Circle { private double radius; public double x; private double y; }

y is available to code that is written outside the Circle class.

For the following code, which statement is not true? public class Sphere { private double radius; public double x; private double y; private double z; }

z is available to code that is written outside the circle class.