Regular Expressions 101

Negative Lookbehind(?<!\w\.\w.)

\wa Unicode word character

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\wa Unicode word character

.any Unicode character (except for line terminators)

Negative Lookbehind(?<![A-Z][a-z]\.)

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

Character Class[a-z]

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Negative Lookbehind(?<![A-Z]\.)

Character Class[A-Z]

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Positive Lookbehind(?<=\.|\?|\!)

1st Alternative\.

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

2nd Alternative\?

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

3rd Alternative\!

\!the literal ! (33₁₀ / 41₈ / 21₁₆)

\sa Unicode whitespace character

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

(?<!\w\.\w.)(?<![A-Z][a-z]\.)(?<![A-Z]\.)(?<=\.|\?|\!)\s

New

A. The following regex is suppose to act as a sentence tokenizer pattern, but I'm having some trouble deciphering what exactly it's doing. C.3. I understand that it's using positive and negative lookbehinds, as the accepted answer of this post explains. But what is considered A in the above regex? Dr. Bob would know! But Mrs. Scholls doesn't.

Regular Expression

Substitution