Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > Perl > Perl Misc > FAQ 4.2 Why is int() broken?

Reply
Thread Tools

FAQ 4.2 Why is int() broken?

 
 
PerlFAQ Server
Guest
Posts: n/a
 
      01-13-2011
This is an excerpt from the latest version perlfaq4.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .

--------------------------------------------------------------------

4.2: Why is int() broken?

Your "int()" is most probably working just fine. It's the numbers that
aren't quite what you think.

First, see the answer to "Why am I getting long decimals (eg,
19.9499999999999) instead of the numbers I should be getting (eg,
19.95)?".

For example, this

print int(0.6/0.2-2), "\n";

will in most computers print 0, not 1, because even such simple numbers
as 0.6 and 0.2 cannot be presented exactly by floating-point numbers.
What you think in the above as 'three' is really more like
2.9999999999999995559.



--------------------------------------------------------------------

The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.

If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
FAQ 5.36 Why can't I use "C:\temp\foo" in DOS paths? Why doesn't `C:\temp\foo.exe` work? PerlFAQ Server Perl Misc 0 04-26-2011 10:00 AM
FAQ 5.38 Why does Perl let me delete read-only files? Why does "-i" clobber protected files? Isn't this a bug in Perl? PerlFAQ Server Perl Misc 0 03-09-2011 11:00 PM
FAQ 5.38 Why does Perl let me delete read-only files? Why does "-i" clobber protected files? Isn't this a bug in Perl? PerlFAQ Server Perl Misc 0 02-11-2011 05:00 AM
why why why why why Mr. SweatyFinger ASP .Net 4 12-21-2006 01:15 PM
findcontrol("PlaceHolderPrice") why why why why why why why why why why why Mr. SweatyFinger ASP .Net 2 12-02-2006 03:46 PM



Advertisments