I want to parse a hh:mm:ss
string.
A simple one is ([0-1]?\d|2[0-3]):([0-5]?\d):([0-5]?\d)
which expects 2:3:24
or 02:03:24
string.
I want to take it a step further and pass the validation even in cases like
Basically, if one ":" is found, consider number before ":" as MM and number after ":" as SS . If two ":" are found consider as HH:MM:SS
I came up with this pattern.
(^([0-1]?\d|2[0-3]):([0-5]?\d):([0-5]?\d)$)|(^([0-5]?\d):([0-5]?\d)$)|(^[0-5]?\d$)
It seems to be working fine. I wanted to know any other simpler regular expression, that can do the job.
^(?:(?:([01]?\d|2[0-3]):)?([0-5]?\d):)?([0-5]?\d)$
Explanation:
^ # Start of string
(?: # Try to match...
(?: # Try to match...
([01]?\d|2[0-3]): # HH:
)? # (optionally).
([0-5]?\d): # MM: (required)
)? # (entire group optional, so either HH:MM:, MM: or nothing)
([0-5]?\d) # SS (required)
$ # End of string