What is the regular expression for the following strings and would the expression change if the number rolled over?

Question

What would be the following regular expressions for the following strings?

56AAA71064D6

56AAA7105A25

Would the regular expression change if the numbers rolled over? What I mean by this is that the above numbers happen to contain hexadecimal values and I don't know how the value changes one it reaches F. Using the first one as an example: 56AAA71064D6, if this went up to 56AAA71064F6 and then the following one would become 56AAA7106406, this would create a different regular expression because where a letter was allowed, now their is a digit, so does this make the regular expression even more difficult. Suggestions?

A manufacturer is going to enter a range of serial numbers. The problems are that different manufacturers have different formats for serial numbers (some are just numbers, some are alpha numeric, some contain extra characters like dashes, some contain hexadacimal values which makes it more difficult because I don't know how the roll over to the next serial number). The roll over issue is the biggest problem because the serial numbers are entered as a range like 5A1B - 6F12 and without knowing how the roll over, it seems to me that storing them in the database is not as easy. I was going to have the option of giving the user the option to input the pattern (expression) and storing that in the databse, but if a character or characters changes from a digit to a letter or vice versa, then the regular expression is no longer valid for certain serial numbers.

Also, the above example I gave is with just one case. There are multitude of serial numbers that would contain different expressions.

Answer 1

There's no single regular expression which is "the" expression to match both of those strings. Instead, there are infinitely many which will do so. Here are two options at opposite ends of the spectrum:

(56AAA71064D6)|(56AAA7105A25)

.*

The first will only match those two strings. The second will match anything. Both satisfy all the criteria you've given.

Now, if you specify more criteria, then we'd be able to give a more reasonable idea of the regular expression to provide - and that will drive the answers to the other questions. (At the moment, the only answer that makes sense is "It depends on what regex you use.")

Answer 2

I think you could do it this way for 12 characters. This will search for a 12 character phrase where each of the characters must be a capital (A or B or C or D or E or F or 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 0)

[A-F0-9]{12}

If you're wanting to include the possibility of dashes then do this.

[A-F0-9\-]{12}

Or you're wanting to include the possibility of dashes plus the 12 characters then do this. But that would pick up any 12-15 character item that fit the criteria though.

[A-F0-9\-]{12,15}

Or if it's surrounded by spaces (AAAAHHHh...SO is stripping out my spaces!!!)

[A-F0-9\-]{12}

Or if it's surrounded by tabs

\t[A-F0-9\-]{12}\t

Answer 3

This match a string that contains 12 hexa

[0-9A-F]{12}

Answer 4

well it sounds like you're describing a 12 digit hexadecimal number:

^[A-F0-9]{12}$

Answer 5

Assuming these are all 12-digit hexadecimal numbers, which it looks like they are, the following regex should work:

[0-9A-Fa-f]{12}

Here I'm using a character class to say that I want any digit, OR A-F, OR a-f. As a bonus I'm allowing lowercase letters; if you don't want those just get them out of the regex.

As Jon Skeet and others have said, you really didn't provide enough information, so if you don't like this answer please understand that I was doing the best I can with what information you provided.

Answer 6

So, why not [0-9A-F]{12}?