Currently using a text field and need some validation for capturing days of a month.
^(?:[1-9]|[12][0-9]|3[01])(?:(?: *- *(?:[1-9]|[12][0-9]|3[01]))?(?: *, *(?:[1-9]|[12][0-9]|3[01])(?: *- *(?:[1-9]|[12][0-9]|3[01]))?)+)?$
My regular expression will allow a value like
1-30, 27, 3, 13.
But not
10-27.
Any suggestions on getting both examples to evaluate correctly?
Tried searching for examples allowing a dash by adding – but received the same result.
>Solution :
You can use
^ # start of string
(?:[1-9]|[12][0-9]|3[01]) # a day pattern
(?: # start of an optional non-capturing group
\ *-\ * # a hyphen enclosed with zero or more spaces
(?:[1-9]|[12][0-9]|3[01]) # a day pattern
)? # end of the optional group
(?: # start of an optional non-capturing group
\ *,\ *(?:[1-9]|[12][0-9]|3[01]) # comma inside optional spaces + day pattern
(?:\ *-\ *(?:[1-9]|[12][0-9]|3[01]))? # an optional sequence of hyphen inside optional spaces + day pattern
)* # repeat zero or more times
$ # end of string
See the regex demo.
A one liner:
^(?:[1-9]|[12][0-9]|3[01])(?: *- *(?:[1-9]|[12][0-9]|3[01]))?(?: *, *(?:[1-9]|[12][0-9]|3[01])(?: *- *(?:[1-9]|[12][0-9]|3[01]))?)*$
See this demo.