ISSN validation.. cannot read integer values from a string..

Question

2.00/5 (1 vote)

See more:

I am trying to read a string which should consist of eight characters, so I can add up the digits and compute the check digit of an ISSN, according to the article described below.

So far the problem is to find a way to count the contents of the array i.e.
ISSN=0378-5955
i.e.
1. add the numeric value of each number for the first seven digits
2. modulus of (1)/11 calculated
if there is no remainder the check digit is 0, otherwise the remainder value is subtracted from 11 to give the check digit

Source:ISSN

public void setISSN(String ISSN)
  {
      String[] ISSNArray = ISSN.Split();
      int [] ISSNSequence = { };
      int SumOfFIrstSevenDigits = 0;
      for (int i = 0; i <= ISSNArray.Length - 1; i++)
      {

      }
  }

Posted 12-Nov-13 7:13am

jon-80

Add a Solution

Comments

Sergey Alexandrovich Kryukov 12-Nov-13 13:24pm

What's the problem? I cannot see where you try to read anything from string.
—SA

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Matt T Heffron · Answer 1 · 2013-11-12T07:39:00

C#

int lastDigit = 0;
// Unicode guarantees the digits are in order and consecutive values
int sum = ISSN.Sum(c => char.IsDigit(c) ? lastDigit = (int)c - (int)'0' : 0);
sum -= lastDigit;
int mod = sum % 11;
int checkDigit = 0;
if (mod != 0)
  checkDigit = 11 - mod;

if (checkDigit == lastDigit)
{
  // true if the lastDigit IS the correct checkDigit
}

The example you gave (0378-5955) appears to be of an invalid ISSN.
The check digit should be 4.

[Edit: since you didn't describe the algorithm correctly, the above didn't do the right thing, so I'll fix it.]

C#

int lastDigit = 0;
int digitPosition = 8;
int sum = ISSN.Sum(c => {
  if (!char.IsDigit(c))
    return 0;
  lastDigit = (int)c - (int)'0';  // Unicode guarantees the digits are in order and consecutive values
  return digitPosition-- * lastDigit;
});
if (digitPosition != 0)
  throw new ArgumentException("Incorrect number of digits in ISSN");
sum -= lastDigit;
int mod = sum % 11;
int checkDigit = 0;
if (mod != 0)
  checkDigit = 11 - mod;

if (checkDigit == lastDigit)
{
  // true if the lastDigit IS the correct checkDigit
}

jon-80 · Answer 2 · 2013-11-12T08:11:00

public void setISSN(String ISSN)
   {
       // validate ISSN
       int[] d = new int[ISSN.Length];
       int c1 = 0; int c2 = 0; int c3 = 0;
       for (int i = 0; i <= ISSN.Length; i++)
       {
           if (i <= 6)
           {
               d[i] = int.Parse(ISSN[i].ToString());
               c1 += d[i];
           }

           c2 = c1 % 11;
           c3 = 0;
           if (c2 == 0) { c3 = 0; }
           else { c3 = 11 - c2; }

           /* Sourced from http://en.wikipedia.org/wiki/International_Standard_Serial_Number,
            * last updated on 23rd September 2013 */
       }
       if (ISSN[6] != c3) throw new System.ArgumentException("ISSN may be invalid", "ISSN Validation");
   }

ISSN validation.. cannot read integer values from a string..

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0