Regular Expressions 101

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/
^(?P<Given>\w+) (?P<Middle>\w\.) (?P<Family>\w+)$
/
mg
^ asserts position at start of a line
Named Capture Group Given
(?P<Given>\w+)
\w
matches any word character (equivalent to [a-zA-Z0-9_])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
matches the character with index 3210 (2016 or 408) literally (case sensitive)
Named Capture Group Middle
(?P<Middle>\w\.)
\w matches any word character (equivalent to [a-zA-Z0-9_])
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
matches the character with index 3210 (2016 or 408) literally (case sensitive)
Named Capture Group Family
(?P<Family>\w+)
\w
matches any word character (equivalent to [a-zA-Z0-9_])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
$ asserts position at the end of a line
Global pattern flags
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
g modifier: global. All matches (don't return after first match)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
mg

Test String