Regular Expressions 101

^start of line

Negated Character Class[^\W\d_]+

+matches at least one character outside the set below:

\Wany non-word character

\da digit

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Non-Capturing Group(?:_[^\W\d_]+)*

*repeats the group contents below any number of times:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Negated Character Class[^\W\d_]+

+matches at least one character outside the set below:

\Wany non-word character

\da digit

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

$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

^[^\W\d_]+(?:_[^\W\d_]+)*$

New

sss
fff_fff
f_f_f_f
sss_
sss@
sss#
sss$

sss
fff_fff
f_f_f_f
sss_
sss@
sss#
sss$