Regular Expressions 101

Non-Capturing Group(?:\b)

\ban ASCII word boundary

Negative Lookahead(?!let)

letthe literal text let (case sensitive)

Positive Lookahead(?=\w+\sfirst_name\s+(know|keep|enjoy))

\w+any word character, repeated at least once

\sany whitespace character

first_namethe literal text first_name (case sensitive)

\s+any whitespace character, repeated at least once

Group 1(know|keep|enjoy)

1st Alternativeknow

knowthe literal text know (case sensitive)

2nd Alternativekeep

keepthe literal text keep (case sensitive)

3rd Alternativeenjoy

enjoythe literal text enjoy (case sensitive)

Group 2(\w+ \w+)

\w+any word character, repeated at least once

the literal (32₁₀ / 40₈ / 20₁₆)

\w+any word character, repeated at least once

\s+any whitespace character, repeated at least once

Group 3(\w+)

\w+any word character, repeated at least once

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

(?:\b)(?!let)(?=\w+\sfirst_name\s+(know|keep|enjoy))(\w+ \w+)\s+(\w+)

New

a reasons first_name keep waking up at night, is blah blah blah. Try this, let first_name know and see blah blah blah. Remember that first_name enjoy being challenged and blah blah blah

Substitution

\2 _object_s