Re: signed int
Re: signed int
- Subject: Re: signed int
- From: "Jerry W. Walker" <email@hidden>
- Date: Wed, 21 Dec 2005 13:52:11 -0500
Hi, Xavier,
I presume you're using Java, since this is a WebObjects mailing list.
If "virtual stock calculation", "quantity available" and "quantity
requested" are each represented by int variables and each of the
latter two hold the values that you're indicating, then I have no
doubt that your calculation is returning a negative result.
If it were doing otherwise, the higher probability would be that your
computer were computing integer arithmetic wrongly. It's happened,
(remember the Pentium snafu), but in my experience, it's only
happened in such obvious ways with esoteric specialized computers,
never mainstream commercial processors that are running Java today.
If your processor (or even the Java's compiled code) were guilty, I
would expect to see a flood of such messages on every Java mailing
list, and so far, yours is the only one I've seen.
I would suggest inserting System.out.println() statements around the
offending calculation. Print out the values of each of the operands
immediately before the calculation, then print out the result
immediately after the calculation. Presuming some reasonable variable
names, do this:
System.out.println("quantityAvailable = " + new Integer
(quantityAvailable));
System.out.println("quantityRequested = " + new Integer
(quantityRequested));
virtualStockCalculation = quantityAvailable - quantityRequested;
System.out.println("virtualStockCalculation = " + new Integer
(virtualStockCalculation));
If the results of the above are yielding a non-negative result and
the operands have the values you described, I would very much like to
see the code. It would help to see the actual code rather than
pseudocode in that case. If the statements that you're representing
with the pseudocode here are scattered throughout a much larger
section of code, it would still help to see the actual declarations
for each of the variables, the actual calculation statement and the
actual statements you use to transfer the result back into some
variable being tested to indicate a non-negative value.
For problems like these, the Devil is in the details, so it helps to
see the details.
Regards,
Jerry
On Dec 21, 2005, at 12:01 PM, Dev WO wrote:
Hi list,
I don't really know where to look for, but here's my issue:
I've got a calculation based on the number (int) of product in stock.
This calculation should lead to negative number sometimes, for
example, if I have a product A which was sold 6 times, if the stock
is 0, the calculation should give -6...but it gives 6?!
Here's a snippet:
--------
quantity available of product A: 0
quantity requested: 6
virtual stock calculation = "quantity available" - "quantity
requested"
--------
This should give -6 but not.
I printed the step to the log to see if it was a number formatting
issue in my wocomponent, but it also displays 6 instead of -6 in
the log.
Any pointer?
Thanks
Xavier
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
40gmail.com
This email sent to email@hidden
--
__ Jerry W. Walker,
WebObjects Developer/Instructor for High Performance Industrial
Strength Internet Enabled Systems
email@hidden
203 278-4085 office
--
__ Jerry W. Walker,
WebObjects Developer/Instructor for High Performance Industrial
Strength Internet Enabled Systems
email@hidden
203 278-4085 office
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
| References: | |
| | >signed int (From: Dev WO <email@hidden>) |