How to get ISBN barcode in iOS

Question

I am doing an ISBN barcode scanning project. I tried many scanning applications, but after scanning this barcode:

the application returns only the barcode 9780749423490. But what I need to get is the code ISBN 0749423498 instead, as in the database of my library. Is there any way to get it?

Can someone explain the difference between these two codes? Why is the barcode number and ISBN barcode number different? Is it the same for some books and for some? thanks!

Answer 1

Confusion seems to be the difference between the ISBN 10 and ISBN 13 standards.

The ISBN FAQ website says:

"Does the ISBN-13 have any meaning imbedded in the numbers? The five parts of an ISBN are as follows: 1. The current ISBN-13 will be prefixed by "978" 2. Group or country identifier which identifies a national or geographic grouping of publishers 3. Publisher identifier which identifies a particular publisher within a group 4. Title identifier which identifies a particular title or edition of a title 5. Check digit is the single digit at the end of the ISBN which validates the ISBN" 

Thus, 978 is clearly a filler. After that, the next 9 numbers are obviously the same in both numbers. The last digit in both numbers is the check digit, which differs in ISBN 10 and ISBN 13. For more details, see this Wikipedia article Formulas:

For ISBN 10 (upper), the sum of all digits multiplied by the bar codes 10-9-8-7-6-5-4-3-2-1 mod 11 should be 0:

 0*10 + 7 *9 + 4*8 + 9*7 + 4*6 + 2*5 + 3*4 + 4*3 + 9*2 + 8*1 % 11 == 0 

For ISBN 13 (lower), the sum of the odd digits * 1 plus the sum of the even digits * 3 should be 0. This includes the leading 978. (this is similar to the UPC code as “user ...” but slightly different, as indicated in Wikipedia article):

 9*1 + 7*3 + 8*1 + 0*3 + 7*1 + 4*3 + 9*1 + 4*3 + 2*1 + 3*3 + 4*1 + 9*3 + 0*1 % 10 == 0 

So, you can get the ISBN code 10 (above) from the ISBN 13 code (below) as follows:

 isbnBaseCode = <9780749423490 from the 4th to 12th characters> isbn10CheckDigit = 11 - (isbnBaseCode[0]*10 + isbnBaseCode[1]*9 + ... + isbnBaseCode[8]*2) % 11 isbnCode10 = isbnBaseCode + isbn10CheckDigit 

Answer 2

Long and short your question is that they are actually both ISBNs. One of them is in ten-digit format, and the other is in 13-bit format.

 978 074942349 0 074942349 8 

978 is the prefix, and the last digit is on the check digit. The barcode of the object you are viewing is in only 13-digit format.

According to http://www.isbn.org/standards/home/isbn/transition.asp you can always convert from a 13-digit ISBN, starting from 978 to a 10-digit format and provides a link to an online converter. It also discusses the prefix 979. I do not believe that the prefix 979 is used, but it is good to know that they can be used in the future.

Having worked in the library application space, when searching the library directory, the entries for the elements will vary greatly in the information that they contain. Records of items, in particular with respect to ISBNs, may contain 10-digit ISBN, 13-digit ISBN, both or none. Therefore, to find an item, you may have to try both formats. I believe that some systems, if your search type is set to ISBN, will actually check the submitted ISBN and automatically search for both formats.

Depending on what you are trying to do. Many library search functions allow you to use wildcards, which can make it easier to find the item you are looking for. For instance:

 'if the isbn has a length of 13 and starts with 978 remove the first 3 (the 978) and last digit (the check digit) add a wildcard character to the front and back begin search end if 

for example, 9780749423490 will become * 07494234 * The disadvantage is that it can return multiple results. Even if this happens, most likely it will be only a couple of objects, and one of yours if there, it would be easy to notice.

As provided by others, the Wikipedia article on ISBN contains more detailed technical information on how to convert between 10 and 13 digit formats. http://en.wikipedia.org/wiki/International_Standard_Book_Number

Answer 3

A number starting with 978 is a product code, in particular UPC (Universal Product Code), which includes ISBN, but without a check digit at the end. Look at the ISBN on wikipedia for the code when generating the check digit, and you can recover the ISBN from the UPC.