Regular Expressions 101

^start of line

{{the literal text {{

\w+any word character, repeated at least once

}}the literal text }}

Non-Capturing Group(?:_{{\w+}})*

*repeats the group contents below any number of times:

_{{the literal text _{{

\w+any word character, repeated at least once

}}the literal text }}

$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.

Search reference

Regular Expression

^{{\w+}}(?:_{{\w+}})*$

Test String
New

{{word1}}_{{word2}}_{{word3}}
_{{word1}}_{{word2}}_{{word3}}.
{{word1}}_word{{word2}}_{{word3}}
{{word1}}_{{word2}}_{{word3}}word4
{{word1}}_{{word2}}_{{word3}}_
_{{word1}}_{{word2}}_{{word3}}_
{{word1}}_{{word2))_{{word3}}
+{{word1}}-{{word2}}_{{word3}
word{{word}}_{{word2}}_

Regular Expression

Test StringNew

SubstitutionProcessing...

Test String
New

Substitution
Processing...