Regular expression for validation

Question

Hi I need to validate New jersey Taxpayer Identification Number The length of this control 12 digits. The validation scenarios: This control contains only 12 digits. all 12 digits are not same. Ex: 111111111111 .. 999999999999 it should not be sequence order like 123456789012 It should not contain last three digits are zeroes like 543044885000 I need one regular expression for all the above scenarios. Thanks' in advance. -- Best Regards Ranganth potluri

Vulpes · Answer

After checking a reference book I have I'm sure that Javascript does support both negative lookahead and back references. However it may not support the latter inside the former as not all regular expressions can be used inside a negative lookahead. So try it like this instead which works in C# as it did before: using System; using System.Text.RegularExpressions; class Program { static void Main() { string[] ids = new string[] { 111111111111 999999999999 123456789012 456789012345 543044885000 124689124000 317238921101 772190300023 }; string repeat = @(?!(111111111111|222222222222|333333333333| + 444444444444|555555555555|666666666666| + 777777777777|888888888888|999999999999| + 000000000000)$); string sequence = @(?!(012345678901|123456789012|234567890123| + 345678901234|456789012345|567890123456| + 678901234567|789012345678|890123456789| + 901234567890)$); string zeros = @(?!\d{9}000$); string digits = @\d{12}; string regExp = String.Format(@^{0}{1}{2}{3}$ repeat sequence zeros digits); foreach(string id in ids) { Console.WriteLine(Regex.IsMatch(id regExp)); } Console.ReadKey(); } }

ranganath potluri · Answer

Hi Vulpes  Thank's for your excellent solution in c#. But it is not working in javascript. please provide me solution for javascript as well. Regards Ranganath potluri

Vulpes · Answer

Well it's messy to put all that into a single regular expression but breaking it down into sub-expressions first the following seems to be working OK in C# : using System; using System.Text.RegularExpressions; class Program { static void Main() { string[] ids = new string[] { 111111111111 999999999999 123456789012 456789012345 543044885000 124689124000 317238921101 772190300023 }; string repeat = @(?!(\d)\1+$); string sequence = @(?!(012345678901|123456789012|234567890123| + 345678901234|456789012345|567890123456| + 678901234567|789012345678|890123456789| + 901234567890)$); string zeros = @(?!\d{9}000$); string digits = @\d{12}; string regExp = String.Format(@^{0}{1}{2}{3}$ repeat sequence zeros digits); foreach(string id in ids) { Console.WriteLine(Regex.IsMatch(id regExp)); } Console.ReadKey(); } } As expected the output (since only the last two are valid) is: False False False False False False True True Perhaps I could leave you to assemble it into a Javascript regular expression. The only advanced features I've used are 'back references' and 'negative lookahead' which hopefully Javascript will support.