sprintf() returning incorrect value

ppeel has asked for the wisdom of the Perl Monks concerning the following question:

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Re: sprintf() returning incorrect value (%.0f) by tye (Sage) on Jul 15, 2015 at 13:41 UTC
`% say "sprintf '%07.0f', 114.6" 0000115` [download] - tye	[reply] [d/l]
Re^2: sprintf() returning incorrect value (%.0f) by ppeel (Novice) on Jul 15, 2015 at 15:37 UTC
Using this syntax works! "sprintf ('%07.0f', $nfc_amt)". Thank you!	[reply]
Re^3: sprintf() returning incorrect value (%.0f) by ikegami (Patriarch) on Jul 15, 2015 at 16:17 UTC
While `%d` truncates (114.999... ⇒ 114), `%f` rounds (114.999... ⇒ 115).	[reply] [d/l] [select]
Re: sprintf() returning incorrect value by toolic (Bishop) on Jul 15, 2015 at 12:59 UTC
You didn't show us how you assigned $nfc_amt. Perhaps... Why am I getting long decimals (eg, 19.9499999999999) instead of the numbers I should be getting (eg, 19.95)?	[reply]
Re: sprintf() returning incorrect value by choroba (Cardinal) on Jul 15, 2015 at 13:01 UTC
How do you populate $nfc_amt? Are you sure it's really 115 integer? `my $n = 114.9999999999999; print "$n\t", sprintf "%07d\n", $n; __END__ Output: 115 0000114` [download] لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ	[reply] [d/l]
Re^2: sprintf() returning incorrect value by ppeel (Novice) on Jul 15, 2015 at 15:29 UTC
I retrieve it from a DB2 table.	[reply]
Re: sprintf() returning incorrect value by hippo (Archbishop) on Jul 15, 2015 at 12:59 UTC
Works fine for me: `$ perl -e ' > $nfc_amt = 114; > print "NFC_AMT before adding zeroes: $nfc_amt\n"; > $nfc_amt = sprintf("%07d", $nfc_amt); > print "NFC_AMT after adding zeroes: $nfc_amt\n"; > ' NFC_AMT before adding zeroes: 114 NFC_AMT after adding zeroes: 0000114` [download] How are you setting `$nfc_amt` in the first place?	[reply] [d/l] [select]
Re: sprintf() returning incorrect value by Anonymous Monk on Jul 15, 2015 at 12:58 UTC
Can't reproduce: `my $nfc_amt = 115; print "NFC_AMT before adding zeroes: $nfc_amt\n"; $nfc_amt = sprintf("%07d", $nfc_amt); print "NFC_AMT after adding zeroes: $nfc_amt\n"; __END__ NFC_AMT before adding zeroes: 115 NFC_AMT after adding zeroes: 0000115` [download] Likely it doesn't contain what you think it contains. Could you add this to your code and show us the output: `use Devel::Peek; Dump($nfc_amt);`	[reply] [d/l] [select]
Re^2: sprintf() returning incorrect value by ppeel (Novice) on Jul 15, 2015 at 15:24 UTC
Added the Dump and this is the result: NFC_AMT before adding zeroes: 115 SV = NFC_AMT after adding zeroes: 0000114 PVNV(0x24cb13c) at 0x256709c REFCNT = 1 FLAGS = (PADMY,NOK,POK,pNOK,pPOK) IV = 0 NV = 115 PV = 0x271042c "115"\0 CUR = 3 LEN = 36	[reply]
Re: sprintf() returning incorrect value by flexvault (Monsignor) on Jul 15, 2015 at 18:10 UTC
Welcome ppeel, This may be my experience only, but I've had problems keeping leading zeros ('0'), in a variable ( especially hashes and arrays ) within a long running script. So instead of using 'sprintf', I usually add a number with the correct number of zeros, and then use 'substr' to remove it when I need to print, etc. So your: `$nfc_amt = sprintf("%07f", $nfc_amt);` [download] becomes for me: `$nfc_amt = $nfc_amt + 10000000; # or $nfc_amt += 10000000;` [download] Then when I need to print/etc. the result, I do: `print "NFC_AMT after adding zeroes: ",substr($nfc_amt,1),"\n";` [download] I have only experienced this when I add the zeros and then use the variables much later. YMMV. (Note: It also could have been a bug in the version of Perl that I was using which is now fixed. :-) Regards...Ed "Well done is better than well said." - Benjamin Franklin	[reply] [d/l] [select]
Re: sprintf() returning incorrect value by pme (Monsignor) on Jul 15, 2015 at 13:03 UTC
Hi ppeel Welcome to the monastery! UPDATE: Sorry, I totally misread your problem. ~~You got what you described. If you need a single leading zero you can get this way:~~ ~~`$nfc_amt = "0$nfc_amt"; # or $nfc_amt = '0' . nfc_amt;`~~ ~~[download]~~	[reply] [d/l]