I have this regEx:
\n1\s(\d{2,8})\s(\d{0,3}(.\d{3}),\d)\s(\w{1,10})\s(\d{0,3}(.\d{3}),\d)\s(\d{0,3}(.\d{3}),\d)\s(\w{3}).+?Ihre Art.-Nr.\s(\d+).+?(?:DeliveryDate:\s(\d{2}.\d{2}.\d{4})).+?(?:ExtraCharge.+?entspricht:\s(\d{0,3}(.\d{3}),\d)\s(\w{1,10}))
Works fine so far. It matches something like this:
1 123456 25,00 Stck 100,00 2.500,00 EUR
. . . some text
Ihre Art.-Nr. 1690431
DeliveryDate: 21.11.2019
. . . some text
incl.ExtraCharge
entspricht: 222,00 EUR
Now I want the bold parts to be optional (in some cases the values are missing in the document).
My idea was to just add a questionmark to the groups:
\n1\s(\d{2,8})\s(\d{0,3}(.\d{3}),\d)\s(\w{1,10})\s(\d{0,3}(.\d{3}),\d)\s(\d{0,3}(.\d{3}),\d)\s(\w{3}).+?Ihre Art.-Nr.\s(\d+).+?(?:DeliveryDate:\s(\d{2}.\d{2}.\d{4}))?.+?(?:ExtraCharge.+?entspricht:\s(\d{0,3}(.\d{3}),\d)\s(\w{1,10}))?
but it doesn't work, and I don't know why
If (?:DeliveryDate:\s(\d{2}.\d{2}.\d{4}))? is not matched, then the regex still expects the .+? before and after to still match.
Try putting the ending .+? inside of the non-capturing group that you have for DeliveryDate. eg
(?:DeliveryDate:\s(\d{2}.\d{2}.\d{4}).+?)?