| (1) | c |
In Java, StringTokenizer is a: |
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| (2) | d |
Two methods in the same class with the same name but different parameters are said to be: |
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| (3) | b |
In Java: |
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| (4) | b |
In Java, if the int named age
is declared protected in the class
Person, age is
accessible/visible in: |
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| (5) | c |
Given the following declaration:
what would be output by the following?
|
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| (6) | d |
In Java, all methods must have: |
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| (7) | c |
In Java, which of the following uses a post test? |
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| (8) | b |
In Java, which of the following statements declares Salaried
as a subclass of PayType?
|
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| (9) | c |
In the Java statement, System.out.println("Hi");,
out is: |
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| (10) | ? |
Working on Programming Assignment 2 was: |
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Item,
Clothing, Food, and Income
classes (in the same
package/directory) and the following declarations and method in
TaxDriver:
public class TaxDriver
{
public static void main(String[] args)
{
Clothing shirt;
double total;
Food lettuce;
Income salary;
Item mop, pan, wax;
Item[] july;
String outString;
july = new Item[10];
salary = new Income("Bonus", 25000.00);
mop = new Item("Swiffer", 8.75);
// The code in the questions below will be inserted here
}
}
indicate which of the following statements will "compile" (C) and which will "not compile" (N), where "compile" means that it will compile without generating an error. Note: Each statement should be considered independently.
In the constructor of the Food class
(after the first line):
|
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| (1) | N |
super.description = "CS239 Rocks!";
|
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| (2) | C |
super(price); (replacing the first line) |
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| (3) | C |
taxRate = 0.20;
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In the main() method of TaxDriver (after
the declarations):
|
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| (4) | C |
mop.taxRate = 0.50;
|
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| (5) | C |
mop.setPrice(9.00);
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| (6) | N |
shirt = new Clothing(10.00);
|
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| (7) | C |
pan = new Item(15.00);
|
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| (8) | C |
wax = new Item("Floor Wax", 3.00);
|
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| (9) | N |
lettuce = new Item("Mixed Greens", 2.50);
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| (10) | N |
outString = salad.toString();
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| (11) | N |
tax = salary.tax();
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| (12) | C |
july[0] = pan; (Assuming pan has been instantiated) |
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| (13) | C |
july[1] = new Item("Toothpaste", 2.59);
|
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| (14) | N |
july[2] = "Lettuce";
|
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| (15) | N |
july[3] = salary; (Assuming salary has been instantiated) |
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For each of the statements above that will "not compile", state why it will not compile. (Provide the statement number in the parentheses.) You do not need to state anything for the statements that will "compile".
(1) description has private access in Item
(6) The Clothing class does not have a corresponding constructor
(and constructors are not inherited).
(9) Incompatible types (you can't assign an
Item to a Food because an Item
isn't a Food).
(10) Cannot find symbol (outString has not been declared).
(11) Cannot find symbol (tax has not been ).
(14) Incompatible types (you can't assign an
String to an Item).
(15) Incompatible types (you can't assign an
Income to an Item even though
the Income class has all of the same methods as
the Item class).
Item,
Clothing, Food, and Income
classes (in the same
package/directory), show what will be
printed by the following driver, assuming everything is compiled and
executed properly.
Notes: (1) Your formatting does not have to be exact, but be careful. (2) The classes in this question do not contain any intentional syntax errors.
public class DogDriver
{
public static void main(String[] args)
{
Clothing shirt;
Food lunch;
Item bone;
Item[] dog;
dog = new Item[3];
bone = new Item("Jumbone", 2.59);
dog[0] = bone;
dog[1] = new Item("Leash", 22.50);
bone.setPrice(1.00);
dog[2] = bone;
for (int i=0; i<dog.length; i++)
{
System.out.println(dog[i].toString());
}
System.out.println();
lunch = new Food("Pizza", 5.00);
System.out.println("Lunch: " + lunch.tax());
shirt = new Clothing("Striped", 10.00);
System.out.println("Shirt: " + shirt.tax());
}
}
Jumbone 1 $ 1.00
Leash 2 $22.50
Jumbone 1 $ 1.00
Lunch: 0.25
Shirt: 3.0
Item, Clothing and
Food classes, complete the
add() and totalTax() methods in the
following Receipt class. Your solution must be
consistent with the comments describing the methods. You must not
change any other methods or attributes. You must not duplicate
any existing code unless it is necessary to do so.
public class Receipt
{
private Item[] items;
private int size;
public Receipt(int maxSize)
{
items = new Item[maxSize];
for (int i=0; i<maxSize; i++)
{
items[i] = null;
}
size = 0;
}
/**
* Adds an Item object to this Receipt (if there are
* not already maxSize elements in it). Specifically,
* this method assigns the Item object to the first null
* element in the array.
*
* @param item The Item object to add
*/
public void add(Item item)
{
if (size < items.length)
{
items[next] = item;
++size;
}
}
/**
* Calculates the total tax of all Item objects in this Receipt.
* Specifically, loops over all of the Item objects
* in this Receipt, gets the tax for each, and adds
* them up. NOTE: This method works properly even if
* the array is only partially full.
*
* @return The total tax
*/
public double totalTax()
{
double total;
total = 0.0;
for (int i=0; i<size; i++)
{
total += items[i].tax();
}
return total;
}
}
getVolume() method, the
isOversized() method, and the two-parameter explicit
value constructor in the following Container class.
Your solution must be consistent with the comments describing the
methods. You must not change any other methods or attributes.
You must not duplicate any existing code unless it is necessary
to do so. (Advice: From a time management perspective, you may
want to work on the explicit value constructor last.)
import java.util.*;
/**
* An encapsulation of a shipping container
*/
public class Container
{
private double depth, height, weight, width;
private static final double LIMIT = 10.00;
private static final double MAX_VOLUME = 1000.00;
private static final double MAX_WEIGHT = 200.00;
/**
* Explicit Value Constructor
*
* @param width The width
* @param height The height
* @param depth The depth
* @param weight The weight
*/
public Container(double width, double height, double depth,
double weight)
{
setAttributes(width, height, depth, weight);
}
/**
* Explicit Value Constructor
*
* This explicit value constructor is passed a String
* representation of the size delimited by 'x' characters
* and a weight. For example, this constructor might be
* used as follows:
*
* container = new Container("10.00x5.00x20.00", 100.00)
*
* where 10.0 is the width, 5.00 is the height, and 20.00 is the depth.
* A standard Container (with size 1 by 1 by 1 and weight 100)
* is constructed if the size is invalid in any way.
*
* @param size A String representation of the size
* @param weight The weight
*/
public Container(String size, double weight)
{
double dvalue, hvalue, wvalue;
String dtoken, htoken, wtoken;
StringTokenizer st;
st = new StringTokenizer(size, "x");
try
{
wtoken = st.nextToken();
htoken = st.nextToken();
dtoken = st.nextToken();
wvalue = Double.parseDouble(wtoken);
hvalue = Double.parseDouble(htoken);
dvalue = Double.parseDouble(dtoken);
setAttributes(wvalue, hvalue, dvalue, weight);
}
catch (NumberFormatException nfe)
{
setAttributes(1.00, 1.00, 1.00, 100.00);
}
catch (NoSuchElementException nsee)
{
setAttributes(1.00, 1.00, 1.00, 100.00);
}
}
/**
* Returns the volume of this Container (which is simply
* the width times the height times the depth)
*/
public double getVolume()
{
return width*height*depth;
}
/**
* Returns true if any or all of the following are true:
*
* The volume is greater than MAX_VOLUME
* The weight is greater than MAX_WEIGHT
* The ratio of the volume to the weight is greater than LIMIT
*/
public boolean isOversized()
{
boolean result;
double ratio, volume;
volume = getVolume();
ratio = volume / weight;
result = (volume > MAX_VOLUME) || (weight > MAX_WEIGHT) ||
(ratio > LIMIT);
//This could also be written as:
//result = false;
//if ((volume > MAX_VOLUME) || (weight > MAX_WEIGHT) ||
// (ratio > LIMIT)) result = true;
return result;
}
/**
* Set all of the attributes of this Container
*
* @param width The width
* @param height The height
* @param depth The depth
* @param weight The weight
*/
private void setAttributes(double width, double height, double depth,
double weight)
{
this.width = Math.abs(width);
this.height = Math.abs(height);
this.depth = Math.abs(depth);
this.weight = Math.abs(weight);
}
}
ATTACHMENTS
public class Item
{
protected static double taxRate = 0.10;
private static int lastCode = 0;
private double price;
private int code;
private String description;
public Item(double price)
{
this("Unknown", price);
}
public Item(String description, double price)
{
this.description = description;
this.price = price;
lastCode++;
code = lastCode;
}
public double getPrice()
{
return price;
}
public void setPrice(double price)
{
this.price = price;
}
public double tax()
{
return taxRate * price;
}
public String toString()
{
return String.format("%10s %3d $%5.2f", description, code, price);
}
}
public class Food extends Item
{
public Food(String description, double price)
{
super(description, price);
}
public double tax()
{
return taxRate/2.0 * getPrice();
}
}
public class Clothing extends Item
{
public Clothing(String description, double price)
{
super(description, price);
}
public double tax()
{
return 2.00 + super.tax();
}
}
public class Income
{
private static double taxRate = 0.10;
private double amount;
private String description;
public Income(String description, double amount)
{
this.description = description;
this.amount = amount;
}
public double tax()
{
return taxRate * amount;
}
}
Copyright 2011