Regular Expressions 101

Pro

^start of line

Positive Lookahead(?=.*?[0-9a-zA-Z])

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

Character Class[0-9a-zA-Z]

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

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

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

Character Class[0-9a-zA-Z]*

*matches any number of characters from the set below:

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

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

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

Character Class[@#$%]

@the literal @ (64₁₀ / 100₈ / 40₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

$the literal $ (36₁₀ / 44₈ / 24₁₆)

%the literal % (37₁₀ / 45₈ / 25₁₆)

Character Class[0-9a-zA-Z]*

*matches any number of characters from the set below:

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

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

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

$end of line

the literal ↵ (10₁₀ / 12₈ / A₁₆)

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.

25 tokens

^(?=.*?[0-9a-zA-Z])[0-9a-zA-Z]*[@#$%][0-9a-zA-Z]*$

New

a@
@a
a@$
a@n01
an01
a
@

a@
@a
a@$
a@n01
an01
a
@