Regular Expressions 101

Explanation
Pro

Non-Capturing Group(?:http:\/\/)?

?repeats the group contents below at most once:

http:the literal text http: (case sensitive)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Non-Capturing Group(?:www\.)?

?repeats the group contents below at most once:

wwwthe literal text www (case sensitive)

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 1([^\?]+)

Negated Character Class[^\?]+

+matches at least one character outside the set below:

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

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

?repeats the group contents below at most once:

\?the literal ? (63₁₀ / 77₈ / 3F₁₆)

.*any character (except for line terminators), repeated any number of times

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Ready to run

26 tokens

(?:http:\/\/)?(?:www\.)?([^\?]+)(?:\?.*)?