hi, can a valid 13-digit ISBN have any character other then digit 0-9? i.e., can a valid 13-digit ISBN contain character 'X'?
views:
170answers:
3
A:
No it can't - the Wikipedia page explains:
The calculation of an ISBN-13 check digit begins with the first 12 digits of the thirteen-digit ISBN (thus excluding the check digit itself). Each digit, from left to right, is alternately multiplied by 1 or 3, then those products are summed modulo 10 to give a value ranging from 0 to 9. Subtracted from 10, that leaves a result from 1 to 10. A zero (0) replaces a ten (10), so, in all cases, a single check digit results.
ChrisF
2010-01-11 11:38:12
and precisely where does it say so?
SilentGhost
2010-01-11 11:40:29
This is not correct: A 13-digit ISBN cannot contain X's, only 10-digit ISBNs (since they do a mod 11 and need to display the value 10 in 1 char)
Lennaert
2010-01-11 11:40:50
I can't find any such examples. The article says: "The International Standard Book Number (ISBN) is a unique[1] numeric commercial book identifier..." It looks like they use x as a placeholder for "any digit".
Costique
2010-01-11 11:41:23
My mistake - sorry
ChrisF
2010-01-11 11:44:09
+5
A:
No, a 10-digit ISBN can, though... See http://en.wikipedia.org/wiki/International_Standard_Book_Number#ISBN-13
Lennaert
2010-01-11 11:39:44
+2
A:
No, a 13-digit ISBN uses modulo 10 in calculation of the check digit, so the check digit can be only 0 to 9. Other digits are also 0 to 9 in any versions of ISBN. See this Wikipedia atricle for details.
sharptooth
2010-01-11 11:42:22