Book Errors / Missing Instructions

OminousAshes · May 2nd, 2015, 01:33 PM

Chapter 7: Try It Out (Implementing Interfaces)

created exceptions (IllegalDeposit, IllegalWithdrawal, IllegalAccount) must have classes created for each one of them that all extend Exception
inside of each of the custom-made exception classes, you will need to either utilize the @SuppressWarnings("serial) annotation right before the class declaration, OR add a default or generated serial version ID. Since I don't currently know what these ID's are used for, I am simply suppressing the serial warnings.
In the CheckingAccount class, inside of the isValidDeposit( ) method, inside of the if statement, remove the "new" in front of BigDecimal.ZERO

Chapter 8: Try It Out (Copying and Showing Files Line by Line with Buffered Streams)

Inside of class FileCopier, inside of the try-with-resources block (specifically, within try's resource declarations within the parentheses after 'try') Change "Reader in" to "BufferedReader in"

itDontMeanAThing · March 10th, 2016, 09:26 AM

I just reported some errata for this book, but first I'd like to mention what a painful and time-consuming process it was. Why on earth I need to create an account and provide personal details such as my mailing address is beyond me. There must have been 30 required fields to complete, and the software doesn't even know which book for which I'm reporting errata, even though I accessed the errata form right from its page. Sigh.

I suspect this will discourage people from reporting errata. I nearly gave up, but persevered with the satisfaction of coming here to express my displeasure.

The errata I reported was:
page 21 - the variable BMI doesn't follow lowerCamelCase and isn't even used in the program.

page 37 - 2 of the 3 array indexes in the MatrixExample are incorrect.

Things like this are frustrating for beginner programmers.

itDontMeanAThing · March 10th, 2016, 09:34 AM

This isn't technically errata, but rather an annoyance that in my opinion should be corrected.

In the introduction the authors state quite clearly, "you will not find the archetypical (and honestly, completely useless) âHello Worldâ example in this book."

I would tend to disagree that a "Hello World" program is useless, and so do the authors, as this program appears twice, first on page 43, and then again on 57.

Code:

/** * This is a simple Java application. 
* It prints a short statement to the standard output. 
*/

class MyFirstApplication {
    public static void main(String[] args){
        System.out.println("I've coded, compiled, and run my first Java program!");
    } 
}

If that isn't a "Hello World" program, I don't know what is. As I mentioned, I think these types of programs do have worth, but I would remove the misleading and "completely useless" comment from the Introduction.

itDontMeanAThing · March 13th, 2016, 09:56 PM

I came across a truly laughable mistake in the book. Have a look at this Enhanced For example from page 143 and see if you can spot the error.

Code:

public class TestClass {
    
    public static void main(String[] args) {
        int[] sales2014 = {500,720,515,377,400,435,510,1010,894,765,992,1125}; 
        int[] staff2014 = {7,5,5,5,5,6,6,7,7,8,9,9}; 
        int[] salesPerStaff = new int[12]; 
        int totalSales2014 = 0;
        
        for (int i: sales2014) {    
            salesPerStaff[i] = sales2014[i]/staff2014[i];
            totalSales2014 = totalSales2014 + sales2014[i]; 
        }
    }   
}

It uses the iterator as an index, and immediately causes an array index out of bounds error. The iterator steps through the sales2014 array, but tries to use the values in the array like an index into the salesPerStaff array. Since the first value in the sales 2014 array is 500, it tries to access salesPerStaff[500] which doesn't exist.

Really disappointing, and quite misleading for readers. This isn't a typo, it's a total conceptual mistake.

And I've noticed numerous little errors throughout the book, like on page 146 where it reads, "You’ve probably noticed that many of the standard for loops shown in this chapter use x as the index name (and x = 0 as the initialization); this is by no means required, but is often used in practice."

Besides the awkward sentence construction, the error is that x hasn't been used once for an index name, it's always been i. These types of little mistakes are scattered throughout this book.

Anyway, I've decided this book is too full of errors to continue to use it, so I won't be reporting any more errata or other issues.

Not recommended.

InfiniteLearning · July 2nd, 2016, 11:29 AM

I've just started reading this book, Beginning Java Programming - Object Oriented Programming, and I've noticed the same errors that were highlighted already, plus another one:

On page 31, in table 2-10, Bitwise Operators, a text error is in the second box area. It says, 'Bitwise OR operator: Puts a 1 bit in the result if one of both input operands have a 1 bit at the given position.'

It should say, '... if one or both input ... ', instead it says ... 'if one of both input ...'.

Fira · August 31st, 2016, 11:20 AM

Same Error in code on pages 101 and 102:

Code:

public static void main(String[] args) {
Book firstBook = new Book("First Book", 2004);
Book secondBook = new Book("Another Book", 2014);
firstBook.sell(200);
System.out.println("Number of copies sold of first book is now: "
+firstBook);
System.out.println("Title of the second book is: "+secondBook.title);
}

Should be:

Code:

public static void main(String[] args) {
Book firstBook = new Book("First Book", 2004);
Book secondBook = new Book("Another Book", 2014);
firstBook.sell(200);
System.out.println("Number of copies sold of first book is now: "
+firstBook.copiesSold);
System.out.println("Title of the second book is: "+secondBook.title);
}

slee1977 · December 21st, 2016, 05:10 PM

Is there a mistake in row 3 of the 'OR' column or is it just me?
Operand 1 = False, Operand 2=True so surely the 'OR' should be True?

gregholst · May 17th, 2018, 08:47 AM

I took all the code of this example in my IDE, but still get a very weird error: When I run the example, I get the "Invalid withdrawal" sometimes at the beginning, sometimes in the end of the "log". I wonder how this inconsistent behaviour can be explained? Maybe some variable is not newly initialised in the re-run?

Also, I find it strange that for the opening of the account one does not use the deposit method. This would be more logical, since it is also used for the bonus given at opening a savings account. Then both processes would have the same validation.

Furthermore, I would prefer if the author gives the correct result (the log) into the book.

In general the topic of the example is good and I also like that the author makes you think how to write the code, instead of providing the correct code after each step.