Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

My Cardinal is signed !

Posted on 2000-04-11
6
Medium Priority
?
243 Views
Last Modified: 2011-04-14
According to the Delphi 3 Help file, cardinals are meant to be a 32 bit unsigned number.

However it is definately a 32 bit signed number on my system. (WinNT)

Try typing '(cardinal($7FFFFFFF)+1)' in the 'evaluate/modify' window and you will get a range check error instead of the correct answer of $80000000.

Also Cardinal($FFFFFFFF) gives '-1'.

Q1. Is this unique to me or does everyone else have the same issue?

Q2. So how do I get a 32 bit unsigned number?  (Simply printing it out differently at the end doesn't help, because the maths in the middle should be correct to)

(For example: $8000 0000 / 2 = ??
  Signed:   $C000 0000
  Unsigned: $4000 0000)

0
Comment
Question by:mac_rowe
  • 2
  • 2
  • 2
6 Comments
 
LVL 12

Accepted Solution

by:
rwilson032697 earned 400 total points
ID: 2706011
I have noticed that various debug windows sometimes 'lie' about the real value of a variable, and at other times can do strange things as you describe.

However, cardinal is NOT a 32 bit unsigned int in D3 - it is a 31 bit unsigned int!

In D5 (D4 too, I think, but not sure) cardinal is a 32 bit unsigned int.

D5 also has LongWord which is 32 bit unsigned, but I am not sure if D3 has this.

You could do the maths in a float variable and round() the result, or it you are just doing things like DIV by 2, then you can use SHR to do it...

Cheers,

Raymond.


0
 
LVL 20

Expert Comment

by:Madshi
ID: 2706680
Ray is right. D3 has no 32bit unsigned support at all. Perhaps you can use the type "comp". Not very handy though.
In D4 Borland introduced "real" 32bit unsigned support with cardinal = longWord = 32bit unsigned.

Regards, Madshi.
0
 
LVL 20

Expert Comment

by:Madshi
ID: 2706684
P.S: You should seriously think about upgrading to D4 or D5, because there are tons of other quite important language extensions like int64 (real 64bit integer type), predefined parameters, function/method overloading and more...
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 

Author Comment

by:mac_rowe
ID: 2710380
Hmm, so the Delphi documentation is a lie.  Didn't someone notice this before they released it ?

Ironically I use D5 at home but here at work we are on good ol' fashioned D3.  When you have several licenses it is quite expensive to upgrade, so I'd like to stick to D3 for the moment, rather than force the entire company to upgrade.

I've found so far the best solution is to turn range checking off and simply pretend that it is unsigned.  It is pretty good apart from the division problem mentioned earlier.

I'll check out a couple of possibilities...

0
 

Author Comment

by:mac_rowe
ID: 2721738
Yes, you get a 'excellent' grade for proving to me that I wasn't mad after all.

0
 
LVL 12

Expert Comment

by:rwilson032697
ID: 2724498
Your welcome!

Cheers,

Raymond.
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

The uses clause is one of those things that just tends to grow and grow. Most of the time this is in the main form, as it's from this form that all others are called. If you have a big application (including many forms), the uses clause in the in…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
Is your data getting by on basic protection measures? In today’s climate of debilitating malware and ransomware—like WannaCry—that may not be enough. You need to establish more than basics, like a recovery plan that protects both data and endpoints.…
Look below the covers at a subform control , and the form that is inside it. Explore properties and see how easy it is to aggregate, get statistics, and synchronize results for your data. A Microsoft Access subform is used to show relevant calcul…

782 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question