I am trying to write a regular expression to allow numbers and only one hypen in the middle (cannot be at start or at the end) say pattern: 02-04 , 02are acceptable but pattern: -- or - or -02 or 04- or 02-04-06 are unacceptable
I tried something like this but this would allow - at the beginning and also allow multiple -
'/^[0-9 \-]+$/'
I am not that good with regex so a little explanation would be real helpful.
EDIT: Sorry to bug you again with this but I need the numbers to be of only 2 digits (123-346) should be considered invalid.
Try this one:
/^\d{1,2}(-\d{1,2})?$/
One or two digits, followed by, optionally, ( a hyphen followed by one or two digits)
Fairly easy:
^\d+(-\d+)?$
At least one (+) digit (\d), followed by an optional group containing a hyphen-minus (-), followed by at least one digit again.
For strings containing only that pattern the following should work
^(\d{2}-)?\d{2}$
A group of 2 digits followed by minus ending with a group of 2 digits without minus.