Regular Expressions 101

Pro

^start of line

Non-Capturing Group(?:[a-z0-9%](?:[a-z0-9 ]*%)?|(?:[<>]=?|!=|%)?[a-z0-9 ]+)

1st Alternative[a-z0-9%](?:[a-z0-9 ]*%)?

Character Class[a-z0-9%]

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

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

%the literal % (37₁₀ / 45₈ / 25₁₆)

Non-Capturing Group(?:[a-z0-9 ]*%)?

?repeats the group contents below at most once:

Character Class[a-z0-9 ]*

*matches any number of characters from the set below:

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

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

the literal (32₁₀ / 40₈ / 20₁₆)

%the literal % (37₁₀ / 45₈ / 25₁₆)

2nd Alternative(?:[<>]=?|!=|%)?[a-z0-9 ]+

Non-Capturing Group(?:[<>]=?|!=|%)?

?repeats the group contents below at most once:

1st Alternative[<>]=?

Character Class[<>]

<the literal < (60₁₀ / 74₈ / 3C₁₆)

>the literal > (62₁₀ / 76₈ / 3E₁₆)

=?optionally matches the literal = (61₁₀ / 75₈ / 3D₁₆)

2nd Alternative!=

!=the literal text !=

3rd Alternative%

%the literal % (37₁₀ / 45₈ / 25₁₆)

Character Class[a-z0-9 ]+

+matches at least one character from the set below:

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

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

the literal (32₁₀ / 40₈ / 20₁₆)

$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.

26 tokens

Regular Expression

^(?:[a-z0-9%](?:[a-z0-9 ]*%)?|(?:[<>]=?|!=|%)?[a-z0-9 ]+)$

New

>test
!=test
<test
>=test
<=test
%test
test
%test%
test%
< 
asdf%
  kj
bd%
%abc%
abc%
1abc%
%%
%
>abc
              
 <
<test%
<test<
>
 %
1%
abc%
<=%
<=abc%
<=

Extraction

>test
!=test
<test
>=test
<=test
%test
test
%test%
test%
< 
asdf%
  kj
bd%
%abc%
abc%
1abc%
%%
%
>abc
              
 <
<test%
<test<
>
 %
1%
abc%
<=%
<=abc%
<=