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  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 677
  • Last Modified:

ISBN Regular Expression

I've got the following code:

function validateISBN(isbn)
{
      if(isbn.length <= 0)
      {
            return true;
      }
      var expression = new RegExp("(?=.{13}$)\d{1,5}([- ])\d{1,7}\1\d{1,6}\1(\d|X)$");

      if (!expression.test(isbn) )
            return false;      
      else
            return true;
      }

but it doesn't appear to work properly. I've taken the RegExp from some ASP code but I'm still very new at this and was wondering if anyone could see where I was going wrong?

Thanx
0
Steven O'Neill
Asked:
Steven O'Neill
  • 3
1 Solution
 
ZvonkoSystems architectCommented:
You are wrong with teh escape character back slash.
If you need one escape character then you need to write two of them.
That is only in String.
To avoid the problem creat the RegExp in its short form.
Like this:
 var expression = /(?=.{13}$)\d{1,5}([- ])\d{1,7}\1\d{1,6}\1(\d|X)$/;

0
 
ZvonkoSystems architectCommented:
In oposite to the short form does the String parameter form looks like this:
 var expression = new RegExp("(?=.{13}$)\\d{1,5}([- ])\\d{1,7}\\1\\d{1,6}\\1(\\d|X)$");

0
 
Steven O'NeillSolutions ArchitectAuthor Commented:
Zvonko

I'm sure the short form works but I've used thge string parameter form.

Thanx
0
 
ZvonkoSystems architectCommented:
Thanks for points.
0

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