How to validate this using Regex C#

Question

I have a input which can be the following (Either one of these three):

• 1-8…in other words 1, 2,3,4,5,6,7,8
• A-Z….in other words, A, B, C, D etc
• 01-98…in other words, 01,02,03,04 etc

I came up with this regex but it's not working not sure why:

@"[A-Z0-9][1-8]-

I am thinking to check for corner cases like just 0 and just 9 after regex check because regex check isn't validating this

Answer 1

Not sure I understand, but how about:

^(?:[A-Z]|[1-8]|0[1-9]|[1-8][0-9]|9[0-8])$

Explanation:

(?:...) is a group without capture.
| introduces an alternative
[A-Z] means one letter
[1-8] one digit between 1 and 8
0[1-9] a 0 followed by a digit between 1 and 9
[1-8][0-9] a digit between 1 and 8 followed by a digit between 1 and 9
9[0-8] 9 followed by a digit between 0 and 8

May be it is, depending on your real needs:

^(?:[A-Z]|[0-9]?[1-8])$

Answer 2

I think you may use this pattern

@"^([1-8A-Z]|0[1-9]|[1-9]{2})$"

Answer 3

What about ^([1-8]|([0-9][0-9])|[A-Z])$ ?

That will give a match for

A 8 (but not 9) 09

Answer 4

[1-8]{0,1}[A-Z]{0,1}\d{1,2}

matches all of the following

8A8 8B9 9 0 00 

Answer 5

You can use following pattern:

^[1-8][A-Z](?:0[1-9]|[1-8][0-9]|9[0-8])$

• ^[1-8] - input should start with number 1-8
• [A-Z] - then should be single letter A-Z
• (0[1-9]|[1-8][0-9]|9[0-8])$ and it should end with two numbers which are 01-19 or 10-89 or 90-98

Test:

string pattern = @"^[1-8][A-Z](0[1-9]|[1-8][0-9]|9[0-8])$";
Regex regex = new Regex(pattern);
string[] valid = { "1A01", "8Z98" };
bool allMatch = valid.All(regex.IsMatch);
string[] invalid = { "0A01", "11A01", "1A1", "1A99", "1A00", "101", "1AA01" };
bool allNotMatch = !invalid.Any(regex.IsMatch);