CODEWITHSUNDEEP
regex
Rafal Xxx
Rafal Xxx

Reputation: 75

How to build regex to match one or the other substring?

In my project, I can have two sentences like:

1) <keyword1> <start_date> <keyword2> <end_date>
2) <keyword1> <end_date>

For example:

1) "Away 01.09.2000 until 03.09.2000"
2) "Away 01.09.2000"

I need to find a match for <end_date> against a value I posses - let's call it <the_date>. I do not know which version of a sentence I have currently, so I need to cover both cases. If <the_date>=03.09.2000 I want the match with sentence 1), but if <the_date>=01.09.2000 I want the match with sentence 2). I tried this regex (it expects spaces to be removed in the sentence), but it seems not working:

\bAway\b([0-9]{2}\.[0-9]{2}\.[0-9]{4}\buntil\b<the_date>|<the_date>(?:(?!\buntil\b))*?)

I know there are many similar questions, but I checked a few and none worked for me.

Thank you and appreciate your effort.

Upvotes: 1

Views: 47

Answers (1)

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 626845

You can consider a pattern like

^Away(?:\s+([0-9]{2}\.[0-9]{2}\.[0-9]{4})\s+until)?\s+01\.09\.2000$

See the regex demo

Details

  • ^ - start of string
  • Away - a word
  • (?:\s+([0-9]{2}\.[0-9]{2}\.[0-9]{4})\s+until)? - an optional occurrence of
    • \s+([0-9]{2}\.[0-9]{2}\.[0-9]{4}) - 1+ whitespace chars and then Group 1 capturing a sequence of two digits, ., two digits, . and four digits
    • \s+until - 1+ whitespace chars and until word
  • \s+ - 1+ whitespace chars
  • 01\.09\.2000 - a 01.09.2000 string
  • $ - end of string.

Upvotes: 1

Related Questions