Regular Expressions 101

^start of line

Negative Lookahead(?!.*([*-]).*\1)

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

Group 1([*-])

Character Class[*-]

*the literal * (42₁₀ / 52₈ / 2A₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

\1the text saved by group 1

Character Class[A-Za-z0-9*-]{1,5}

{1,5}matches between 1 and 5 characters from the set below:

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

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

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

*the literal * (42₁₀ / 52₈ / 2A₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

$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

Detailed match information will be displayed here automatically.

26 tokens

Regular Expression

^(?!.*([*-]).*\1)[A-Za-z0-9*-]{1,5}$

New

matched strings

abcds
a*a1a
11*a-
-a*hu
124ed
0-aur
ABC
8*-a
a

not matched string

**ab1
--ahy
0-a-*
111-*1
abcdef
u-a-r

matched strings

abcds
a*a1a
11*a-
-a*hu
124ed
0-aur
ABC
8*-a
a

not matched string

**ab1
--ahy
0-a-*
111-*1
abcdef
u-a-r