Regular Expressions 101

Pro

(?i)applies the following effective flags to the remainder of the pattern: gmi

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

^start of line

Negative Lookahead(?!.*\bnever\b.{,20}\bwater\b)

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

\ba Unicode word boundary

neverthe literal text never (case insensitive)

\ba Unicode word boundary

.{,20}any Unicode character (except for line terminators), repeated between 0 and 20 times

\ba Unicode word boundary

waterthe literal text water (case insensitive)

\ba Unicode word boundary

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

\ba Unicode word boundary

waterthe literal text water (case insensitive)

\ba Unicode word boundary

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

Regular Expression

(?i)^(?!.*\bnever\b.{,20}\bwater\b).*\bwater\b

New

water
I have water
I never have water
Where is the water
I never have food or water
I never have food but I always have water
I never have food or chips. I like to walk. I have water

Substitution

water
I have water
I never have water
Where is the water
I never have food or water
I never have food but I always have water
I never have food or chips. I like to walk. I have water