Regular Expressions 101

Pro

1st Alternative(?<=\bcow )(?:(?!\bbuys\b).)*(?= milk\b)

Positive Lookbehind(?<=\bcow )

\ban ASCII word boundary

cow the literal text cow (case sensitive)

Non-Capturing Group(?:(?!\bbuys\b).)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\bbuys\b)

\ban ASCII word boundary

buysthe literal text buys (case sensitive)

\ban ASCII word boundary

.any character (except for line terminators)

Positive Lookahead(?= milk\b)

milkthe literal text milk (case sensitive)

\ban ASCII word boundary

2nd Alternative(?<=\bgoat )(?:(?!\bbuys\b).)*(?= milk\b)

Positive Lookbehind(?<=\bgoat )

\ban ASCII word boundary

goat the literal text goat (case sensitive)

Non-Capturing Group(?:(?!\bbuys\b).)*

*repeats the group contents below any number of times:

Negative Lookahead(?!\bbuys\b)

\ban ASCII word boundary

buysthe literal text buys (case sensitive)

\ban ASCII word boundary

.any character (except for line terminators)

Positive Lookahead(?= milk\b)

milkthe literal text milk (case sensitive)

\ban ASCII 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

(?<=\bcow )(?:(?!\bbuys\b).)*(?= milk\b)|(?<=\bgoat )(?:(?!\bbuys\b).)*(?= milk\b)

New

My cow always gives milk
My goat sometimes gives milk
My giraffe always gives milk
My goat always buys milk

My cow always gives milk
My goat sometimes gives milk
My giraffe always gives milk
My goat always buys milk