Regular Expressions 101

Pro

Character Class[ ]

the literal (32₁₀ / 40₈ / 20₁₆)

Positive Lookahead(?=[^\][\s]+(?:\[[^\][]*])?(?!\S))

Negated Character Class[^\][\s]+

+matches at least one character outside the set below:

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

[the literal [ (91₁₀ / 133₈ / 5B₁₆)

\sany whitespace character

Non-Capturing Group(?:\[[^\][]*])?

?repeats the group contents below at most once:

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

Negated Character Class[^\][]*

*matches any number of characters outside the set below:

\]the literal ] (93₁₀ / 135₈ / 5D₁₆)

[the literal [ (91₁₀ / 133₈ / 5B₁₆)

]the literal ] (93₁₀ / 135₈ / 5D₁₆)

Negative Lookahead(?!\S)

\Sany non-whitespace character

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

[ ](?=[^\][\s]+(?:\[[^\][]*])?(?!\S))

New

tree car[tesla BMW] cat color[yellow blue] dog
tree car[tesla BMW] cat xml:cat xml:color[yellow blue] dog
tree car[tesla BMW] cat color yellow blue] dog
tree car[tesla BMW] cat color[yellow blue dog

Extraction

tree car[tesla BMW] cat color[yellow blue] dog
tree car[tesla BMW] cat xml:cat xml:color[yellow blue] dog
tree car[tesla BMW] cat color yellow blue] dog
tree car[tesla BMW] cat color[yellow blue dog