Regular Expressions 101

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/
(\b(\w)(\w+))
/
gm
1st Capturing Group
(\b(\w)(\w+))
\b assert position at a word boundary: (^\w|\w$|\W\w|\w\W)
2nd Capturing Group
(\w)
\w matches any word character (equivalent to [a-zA-Z0-9_])
3rd Capturing Group
(\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)
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Your regular expression does not match the subject string.Try launching the debugger to find out why.

Regular Expression
No Match

/
/
gm

Test String

Substitution

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