Regular Expressions 101

Explanation

Pro

Positive Lookbehind(?<=\*)

\*the literal * (42₁₀ / 52₈ / 2A₁₆)

Non-Capturing Group(?:0\d{3}|1[0-8]\d{2}|19[0-2]\d)

1st Alternative0\d{3}

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\d{3}a Unicode decimal digit, repeated exactly 3 times

2nd Alternative1[0-8]\d{2}

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-8]

0-8one character from 0 (48₁₀) to 8 (56₁₀)

\d{2}a Unicode decimal digit, repeated exactly 2 times

3rd Alternative19[0-2]\d

19the literal text 19

Character Class[0-2]

0-2one character from 0 (48₁₀) to 2 (50₁₀)

\da Unicode decimal digit

Negative Lookahead(?!\d)

\da Unicode decimal digit

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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

(?<=\*)(?:0\d{3}|1[0-8]\d{2}|19[0-2]\d)(?!\d)

New

'The **ALI**1929 for 90 days but not 77731929',
'For all **ALI**1952  28A 177945 ',
'But the **ALI**1914 and **ALI**1903 1912'

*0040
*1234
*1299
*9999
*1952
*1727

Substitution

OLDER

'The **ALI**1929 for 90 days but not 77731929',
'For all **ALI**1952  28A 177945 ',
'But the **ALI**1914 and **ALI**1903 1912'

*0040
*1234
*1299
*9999
*1952
*1727