Regular Expressions 101

Non-Capturing Group(?:^|(?<=[\s:]))

1st Alternative^

^start of line

2nd Alternative(?<=[\s:])

Positive Lookbehind(?<=[\s:])

Character Class[\s:]

\sa Unicode whitespace character

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Group 1(:[^\s:]+:)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Negated Character Class[^\s:]+

+matches at least one character outside the set below:

\sa Unicode whitespace character

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Positive Lookahead(?=[\s:]|$)

1st Alternative[\s:]

Character Class[\s:]

\sa Unicode whitespace character

:the literal : (58₁₀ / 72₈ / 3A₁₆)

2nd Alternative$

$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

(?:^|(?<=[\s:]))(:[^\s:]+:)(?=[\s:]|$)

:match1::match2: :match3:
:match4:
000:matchNot:
:matchNot:000
:match Not: