Regular Expressions 101

(?s)applies the following effective flags to the remainder of the pattern: gs

s modifier: single line. Allows a dot to match line terminators

Negated Character Class[^\n]*

*matches any number of characters outside the set below:

\na line-feed (newline) character (ASCII 10)

\ban ASCII word boundary

littlethe literal text little (case sensitive)

\ban ASCII word boundary

Non-Capturing Group(?:(?!\blittle\b|\bfleece\b).)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\blittle\b|\bfleece\b)

1st Alternative\blittle\b

\ban ASCII word boundary

littlethe literal text little (case sensitive)

\ban ASCII word boundary

2nd Alternative\bfleece\b

\ban ASCII word boundary

fleecethe literal text fleece (case sensitive)

\ban ASCII word boundary

.any character

fleecethe literal text fleece (case sensitive)

Negated Character Class[^\n]*

*matches any number of characters outside the set below:

\na line-feed (newline) character (ASCII 10)

Non-Capturing Group(?:\n[^\n]*){4}

{4}repeats the group contents below exactly 4 times:

\na line-feed (newline) character (ASCII 10)

Negated Character Class[^\n]*

*matches any number of characters outside the set below:

\na line-feed (newline) character (ASCII 10)

Global pattern flags

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

Detailed match information will be displayed here automatically.

25 tokens

Regular Expression

(?s)[^\n]*\blittle\b(?:(?!\blittle\b|\bfleece\b).)*fleece[^\n]*(?:\n[^\n]*){4}

New

1.Mary had a little lamb,
2.Little lamb, little lamb,
3.Mary had a little lamb,
4.Its fleece was white as snow
5.And everywhere that Mary went,
6.Mary went, Mary went,
7.Everywhere that Mary went
8.The lamb was sure to go
9.It followed her to school one day
10.School one day, school one day
11.It followed her to school one day
12.Which was against the rules.