Regular Expressions 101

Pro

\ban ASCII word boundary

foothe literal text foo (case sensitive)

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

?repeats the group contents below at most once:

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

\w+any word character, repeated at least once

\ban ASCII word boundary

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

Regular Expression

\bfoo(?:_\w+)?\b

New

xxxx xxxx xx xxxx xxx foo xxx xxx xxxxx

xxxx xx foo xxx xxx xxxxx

xx xxxxx xxxx xx xxx xx bar xx xxxx

xxxxxx xx xxxxx x xxxx bar

xxx xxxxx xx xx foo_sub1 xxx xxxx

xx foo_sub2 xxxxx xxx x xxxx

xxx xx foo1_sub1 xxx xxxx

xxxxx foo1_sub2 xxxxx xxx x xxxx