Regular Expressions 101

Pro

Positive Lookbehind(?<=(?<!\?)(?:\?\?)*)

Negative Lookbehind(?<!\?)

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

Non-Capturing Group(?:\?\?)*

*repeats the group contents below any number of times:

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

'the literal ' (39₁₀ / 47₈ / 27₁₆)

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

(?<=(?<!\?)(?:\?\?)*)'

?' => shouldn't match (preceded by one ?)
??' => Should match (preceded by 2 ?)
?????' => Shouldn't match (preceded by 5 ?)

?' => shouldn't match (preceded by one ?)
??' => Should match (preceded by 2 ?)
?????' => Shouldn't match (preceded by 5 ?)