问题
I'm terible with regex and I can't seem to wrap my head around this simple task.
I need to parse out the two dates in a string which always has one of two formats:
"Inquiry at your property for December 29, 2013 - January 03, 2014"
OR
"Inquiry at your property for 29 December , 2013 - 03 January, 2014"
the 2 different date formats are throwing me off. Any insights would be appreciated!
回答1:
/(\d+ \w+, \d+|\w+ \d+, \d+)/ for example. Try it out on Rubular.
For sure, it would pickup more stuff, like 2013 NotReallyAMonth, 12345. But if you don't have things in the input that look like a date, but not actually a date this might work.
You could make the regexp stronger, but applying more restrictions on what is matched:
/(\d{2} (?:January|December), \d{4}|(?:January|December) \d{2}, \d{4})/
In this case the day is always two digits, the year is 4. Months are listed explicitly (you would have to list all of them).
Update: For ranges it would be a different regexp:
/((?:Jan|Dec) \d+ - \d+, \d{4})/
Obviously they can all be combined together:
/(\d{2} (?:January|December), \d{4}|(?:January|December) \d{2}, \d{4}|(?:Jan|Dec) \d+ - \d+, \d{4})/
来源：https://stackoverflow.com/questions/19548809/parsing-dates-from-string-regex