regex101: PCRE2 (PHP) Substitution Workspace

Non-Capturing Group(?:^[A-Za-z].*\R\K|(?!^)\G)

1st Alternative^[A-Za-z].*\R\K

^start of line

Character Class[A-Za-z]

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

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

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

\Ra newline sequence

\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match

2nd Alternative(?!^)\G

Negative Lookahead(?!^)

^start of line

\Gstart of current search

Positive Lookahead(?=(?:[A-Za-z].*\R)*(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\d{4}\b)

Non-Capturing Group(?:[A-Za-z].*\R)*

*repeats the group contents below any number of times:

Character Class[A-Za-z]

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

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

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

\Ra newline sequence

Non-Capturing Group(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)

1st AlternativeJan

Janthe literal text Jan (case sensitive)

2nd AlternativeFeb

Febthe literal text Feb (case sensitive)

3rd AlternativeMar

Marthe literal text Mar (case sensitive)

4th AlternativeApr

Aprthe literal text Apr (case sensitive)

5th AlternativeMay

Maythe literal text May (case sensitive)

6th AlternativeJun

Junthe literal text Jun (case sensitive)

7th AlternativeJul

Julthe literal text Jul (case sensitive)

8th AlternativeAug

Augthe literal text Aug (case sensitive)

9th AlternativeSep

Septhe literal text Sep (case sensitive)

10th AlternativeOct

Octthe literal text Oct (case sensitive)

11th AlternativeNov

Novthe literal text Nov (case sensitive)

12th AlternativeDec

Decthe literal text Dec (case sensitive)

\d{4}a digit, repeated exactly 4 times

\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

Search reference

Regular Expression

(?:^[A-Za-z].*\R\K|(?!^)\G)(?=(?:[A-Za-z].*\R)*(?:Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\d{4}\b)

Test String
New

Xbo
Play
Sep2018
/////////////////////////
reregg
95959
1151
Zbo
Tlay
Jul2018

Substitution
Processing...

0\n

Regular Expression

Test StringNew

SubstitutionProcessing...

Test String
New

Substitution
Processing...