How to generate unique alphanumeric max 50 character string?

Question

Hello, I would like to know how to create unique alphanumeric max 50 character string. What is the chance of getting the same string by the way? I have more than one client, I don't want strings to be overlapped. Best Regards.

Mario Scheeren · Answer

A really simple solution is this: static Random _Random = new Random(); static char [] _AllowedChars = Enumerable.Range(48, 10).Select(x => ( char )x) .Concat(Enumerable.Range(65, 26).Select(x => ( char )x)) .Concat(Enumerable.Range(97, 26).Select(x => ( char )x)) .ToArray(); static string PseudoUniqueString( int maxLength = 50) => new string (Enumerable.Range(1, Math.Max(1, maxLength)) .Select(x => _AllowedChars[_Random.Next(_AllowedChars.Length)]) .ToArray());

Mario Scheeren · Answer

I am not good in calculating this, but if you really want to narrow it down further, you could put them in a static list, having an expiring timestamp so that you could look up values for duplicates. But actually I don't think you will get that much overlaps. You could possibly add an useralias before that also, making it even more impossible to get dups.

Cenk · Answer

Hi Mario, Thanks for your reply. What is the chance of generating the same string? I am planning to use this unique string for transactions in my web api.

How to generate unique alphanumeric max 50 character string?

Answers (3)