Regular Expressions 101

Pro

^start of line

Group 1((?!\bdefine\b).)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\bdefine\b)

\ban ASCII word boundary

definethe literal text define (case sensitive)

\ban ASCII word boundary

.any character (except for line terminators)

$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.

25 tokens

^((?!\bdefine\b).)*$

New

Hello define
This word is defined here.
define is not allowed.