C# Cookbook
by Stephen Teilhet, Jay Hilyard

This errata page lists errors outstanding in the most recent printing.

If you have technical questions or error reports, you can send them to
booktech@oreilly.com.  Please specify the printing date of your copy.

This page was updated January 21, 2005.

Here's a key to the markup:
	[page-number]: serious technical mistake
	{page-number}: minor technical mistake
	<page-number>: important language/formatting problem
	(page-number): language change or minor formatting problem
	?page-number?: reader question or request for clarification



Confirmed errors:


{52} first paragraph of the discussion;
        Any value larger than 127 is converted to the ? character.

Should read:

        Any value larger than 127 will be AND'ed with the value 127 and the
resulting character value will be displayed in the string. For example, if
the byte array contains the value 200, this value will be converted to 72,
and the character equivalent of 72 ('H') will be displayed.


[235]  Last code solution;
The solution code:

if ((lang | (Language.CSharp | Language.VBNET)) ==
    (Language.CSharp | Language.VBNET))
{
   // lang contains only the Language.CSharp and Language.VBNET
}

There is one bug in this code due to the fact that a developer could set the
lang variable to any integer value. Basically, the code works for any value
for lang that is greater than zero. So, the following is true:

        For lang values of 1 (CSharp), 2 (VBNET), or 3 (CSharp | VBNET) the
expression evaluates to true, which it does.
        For lang values of 4 (VB6) or greater (CSharp | VBNET | VB6) the
expression evaluates to false, which it does.
However,
        For a lang value of 0 (not defined in the Language enum) the
expression SHOULD (in this case) evalutate to false, which it does not.


If the Language enumeration were written as:
        enum Language
        {
                ALL=0, CSharp=1, VBNET=2, ...
        }
Then the if statement would evaluate correctly, but who writes enumerations
like this. Usually the ALL enumeration value is equal to all the relevent
bits turned on (e.g. ALL=16). So to fix this problem we can add an extra if
statement to make sure that the enumeration value contained in the lang
variable is greater than zero, as shown here:

        if (lang > 0)
        {
                if ((lang | (Language.CSharp | Language.VBNET)) ==
                   (Language.CSharp | Language.VBNET))
                {
                        // lang contains only the Language.CSharp and Language.VBNET
                }
        }