Re: 0.123, float or integer

guha,

That is weird. Well either something is forcing the initial scalar to integer or afterwards forcing the product to integer. I would say Devel::Peek is your friend. Place some Dump calls before and after your multiplication and check for NV, IV, and PV values.

#!/usr/local/bin/perl -wd

use Devel::Peek;

$v = "21.654";
$w = 2;
$x = "";
$x = $w * $v;
Dump( $x );
$x = int($x);
Dump( $x );
[download]

-derby

Comment on Re: 0.123, float or integer Download Code

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Re: Re: 0.123, float or integer by guha (Priest) on Feb 06, 2002 at 10:22 UTC
After a good nights sleep I looked more thoroughly using Devel::Peek as you pointed me to. And now I think we're closing in. In the test script: `Dump($v2); ## prints SV = PV(0x176ec38) at 0x1765274 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x17601c0 "3.25"\0 CUR = 4 LEN = 8 my $v3 = 2.5 * $v2; Dump($v3); ## prints SV = NV(0x1761830) at 0x177ee88 REFCNT = 1 FLAGS = (PADBUSY,PADMY,NOK,pNOK) NV = 8.125` [download] BUT with the original program `Dump($v2); ## prints SV = PV(0x1b69008) at 0x1b87164 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x1b6ab58 "3.25"\0 CUR = 4 LEN = 5 my $v3 = 2.5 * $v2; Dump($v3); ## prints SV = NV(0x178ecbc) at 0x1b87218 REFCNT = 1 FLAGS = (PADBUSY,PADMY,NOK,pNOK) NV = 7,5` [download] From this I gather that the problem has something to do with the decimal delimiter, maybe the locale or somesuch has been changed under my feet. The difference between the original script and the test is that the original uses DBI I will now upgrade my Activestate 623 distribution to 631 to see if this resolves the problem More ideas ? --- It's unfair to be an expert.	[reply] [d/l] [select]
Re: Re: Re: 0.123, float or integer by jmcnamara (Monsignor) on Feb 06, 2002 at 10:57 UTC
Well done. That's interesting. I've been bitten by that before but not in Perl. `perl -le 'print 2 * "21.654"' # 43.308 perl -le 'print 2 * "21,654"' # 42` [download] -- John.	[reply] [d/l]
Re: Re: 0.123, float or integer by guha (Priest) on Feb 05, 2002 at 23:55 UTC
A quick test with Devel::Peek revealed the following info: `Testscript: SV = PV(0x176ec4c) at 0x1765288 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) PV = 0x17601c0 "0.123"\0 CUR = 5 LEN = 8` [download] `Original program: SV = PVIV(0x1adb6f4) at 0x1b874d8 REFCNT = 1 FLAGS = (PADBUSY,PADMY,POK,pPOK) IV = 0 PV = 0x1ade30c "83.4"\0 CUR = 4 LEN = 8` [download] Perhaps because it's late at night but, I can't figure out anything else than that the number is interpreted as a string. But that is odd too, I thought a string would evaluate to zero or the number not int($number) ??? --- It's unfair to be an expert.	[reply] [d/l] [select]