Find a 'q' not followed by an 'u'
matches the 'q' in "Iraq" but not in "question"
Find a 'q' followed by an 'u':
matches the 'q' in "question" but not in "Iraq"
Find an 'u' without a 'q' in front of it: matches the 'u' in "Iraq" but not in "question"
find an 'u' with a 'q' in front of it: matches the 'u' in "question" but not in "Iraq"
Important note:
The used regex library has a limitation that look ahead must be at the end of the regular expression, and look behind must be at the start. Otherwise an error will be shown.
matches the 'u' in "Iraq"
doesn't match the 'u' in "Iraq"
The u in Iraq must be buried deep, because I don't see it
Looks like a copy and paste error. I think it should be like this:
Negative look behind: Find a 'q' without an 'a' in front of it:
(?<!a)q matches the 'q' in "question" but not in "Iraq"
Positive look behind: find a 'q' with an 'a' in front of it:
(?<=a)q matches the 'q' in "Iraq" but not in "question"
Negative look behind: Find a 'q' without an 'a' in front of it:
(?<!a)q matches the 'q' in "question" but not in "Iraq"
Positive look behind: find a 'q' with an 'a' in front of it:
(?<=a)q matches the 'q' in "Iraq" but not in "question"
German help is bad:
Negativer Blick nach hinten: Sucht ein 'q' ohne ein 'a' davor:
(?<!a)q findet das 'q' in "Iraq" aber nicht in "Qual"
Positiver Blick nach hinten: Sucht ein 'q' mit einem 'a' davor:
(?<=a)q findet das 'q' in "Qual" aber nicht in "Iraq"
