Regular Expression to validate a CAGE Code

Question

We need to write a RegEx which can validate a CAGE Code

A CAGE Code is a five (5) position code. The format of the code is

• the first and fifth position must be numeric.
• The second, third and fourth may be any mixture of alpha/numeric excluding alpha letters I and O.
• Case insensitive

We came up with a RegEx cageCode = new RegEx(/^[a-zA-Z0-9]{5}$/) which is not properly validating the requirements given.

What could be the possible regEx which could validate the requirements mentioned?

Answer 1

You're trying to match 5 characters which could be either numbers or letters. Try something like this:

^\d(?:(?![ioIO])[A-Za-z\d]){3}\d$

To break it down:

1. ^\d: Will check if the string starts with a number
2. (?:(?![ioIO])[A-Za-z\d]){3}: To check if there are 3 alphanumeric characters except i/o/I/O
3. \d$: To validate if the string ends with a number