troubleshooting Question

# Complex Regular Expression for a form validation asked on
JavaScriptScripting LanguagesjQuery
I have this form that validates with jquery & regular expressions...

``````...
//some code

var characterReg = /^([a-zA-Z0-9]{2,50})\$/; //only letters and numbers

if ( !characterReg.test(inputValName) ){

result.text('that\'s not a valid name!');

...
//more code
``````

Now, I need a very specific validation of a field called 'NIF', wich is the identifier of a tax-paying company in my country. And I need some help to make a regular expression to use like I did in the above code.

So I found an old javascript code online that validates 'NIF':

``````function IsValidNIF(nif)
{
var c;
var checkDigit = 0;
//Check if is not null, is numeric and if has 9 numbers
if(nif != null && IsNumeric(nif) && nif.length == 9)
{
//Get the first number of NIF
c = nif.charAt(0);
//Check firt number is (1, 2, 5, 6, 8 or 9)
if(c == ‘1' || c == ‘2' || c == ‘5' || c == ‘6' || c == ‘8' || c == ‘9')
{
//Perform CheckDigit calculations
checkDigit = c * 9;
var i = 0;
for(i = 2; i <= 8; i++)
{
checkDigit += nif.charAt(i-1) * (10-i);
}
checkDigit = 11 - (checkDigit % 11);
//if checkDigit is higher than ten set it to zero
if(checkDigit >= 10)
checkDigit = 0;
//Compare checkDigit with the last number of NIF
//If equal the NIF is Valid.
if(checkDigit == nif.charAt(8))
return true;
}
}
return false;
}

function IsNumeric(ObjVal)
{
return /^\d+\$/.test(ObjVal);
}
``````

So, is it possible to make a regular expression from this?

The rules are:

-must be only numbers
-must be 9 characters(numbers) long
-the first number must be 1 or 2 or 5 or 6 or 8 or 9
-the last number performs some validation(%module) that you should understand viewing the above code

Thank you.
Join the community to see this answer!
###### Learn from the best

Network and collaborate with thousands of CTOs, CISOs, and IT Pros rooting for you and your success.

Andrew Hancock - VMware vExpert
See if this solution works for you by signing up for a 7 day free trial.