Regular Expressions 101

Pro

^start of line

Negative Lookahead(?!\s)

\sany whitespace character

Character Class[a-zA-Z\d$#@ ]{1,5}

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

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

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

\da digit

$the literal $ (36₁₀ / 44₈ / 24₁₆)

#the literal # (35₁₀ / 43₈ / 23₁₆)

@the literal @ (64₁₀ / 100₈ / 40₁₆)

the literal (32₁₀ / 40₈ / 20₁₆)

Negative Lookbehind(?<!\s)

\sany whitespace 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

Detailed match information will be displayed here automatically.

25 tokens

^(?!\s)[a-zA-Z\d$#@ ]{1,5}(?<!\s)$

Hell@
He @@
Hel@ 
 Hell
Hel %
Hell%