Regular Expressions 101

Explanation
Pro

Positive Lookbehind(?<=,\s)

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\sa Unicode whitespace character

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

Positive Lookahead(?=\s\d)

\sa Unicode whitespace character

\da Unicode decimal digit

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

(?<=,\s).*(?=\s\d)

New

"12345 Big Street, New York 12345 United States"

"12345 Big Street, New York 12345 United States"