Regular Expressions 101

^start of line

Negative Lookahead(?!(?=.*\bhede\b))

Positive Lookahead(?=.*\bhede\b)

.*any character (except for line terminators), repeated any number of times

\ban ASCII word boundary

hedethe literal text hede (case sensitive)

\ban ASCII word boundary

.*any character (except for line terminators), repeated any number of times

$end of line

Global pattern flags

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

m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

^(?!(?=.*\bhede\b)).*$

New

hoho
hihi
haha
hede
some words before hoho some words after that
some words before hihi some words after that
some words before haha some words after that
some words before hede some words after that
ahede

Regular Expression

Extraction