Regular Expressions 101

1st Alternative\.([0-9a-z]+)(?=[?#])

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 1([0-9a-z]+)

Character Class[0-9a-z]+

+matches at least one character from the set below:

0-9one character from 0 (48₁₀) to 9 (57₁₀)

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

Positive Lookahead(?=[?#])

Character Class[?#]

?the literal ? (63₁₀ / 77₈ / 3F₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

2nd Alternative(\.)(?:[\w]+)$

Group 2(\.)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Non-Capturing Group(?:[\w]+)

Character Class[\w]+

+matches at least one character from the set below:

\wany word character

$end of line

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

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

Detailed match information will be displayed here automatically.

Search reference

Regular Expression

\.([0-9a-z]+)(?=[?#])|(\.)(?:[\w]+)$

Test String
New

css/global.css?_1452687176804
deneme.asp
index.html?a=deneme
default.asp?
jquery.min.js
karma.config.js
sayfalar.asp#birincis
311.html
a.playlist
b.plist
a.123

Regular Expression

Test StringNew

SubstitutionProcessing...

Test String
New

Substitution
Processing...