Regex how to match an optional character
You can make the single letter optional by adding a ?
after it as:
([A-Z]{1}?)
The quantifier {1}
is redundant so you can drop it.
Use
[A-Z]?
to make the letter optional. {1}
is redundant. (Of course you could also write [A-Z]{0,1}
which would mean the same, but that's what the ?
is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-Z]{3})\s+([A-Z])[0-9]{3}([0-9]{4})([0-9]{2})([0-9]{2})
And, since in most regex dialects, \d
is the same as [0-9]
:
^(\d{5})+\s+([A-Z]?)\s+([A-Z])(\d{3})(\d{3})([A-Z]{3})([A-Z]{3})\s+([A-Z])\d{3}(\d{4})(\d{2})(\d{2})
But: do you really need 11 separate capturing groups? And if so, why don't you capture the fourth-to-last group of digits?