Regular Expressions 101

Pro

Character Class[+-]?

?matches at most one character from the set below:

+the literal + (43₁₀ / 53₈ / 2B₁₆)

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 1(\d*|\d{1,3}(,\d{3})*)

1st Alternative\d*

\d*a digit, repeated any number of times

2nd Alternative\d{1,3}(,\d{3})*

\d{1,3}a digit, repeated between 1 and 3 times

Group 2(,\d{3})*

*repeats the group contents below any number of times:

,the literal , (44₁₀ / 54₈ / 2C₁₆)

\d{3}a digit, repeated exactly 3 times

Group 3(\.\d+)?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d+a digit, repeated at least once

\ban ASCII word boundary

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

[+-]?(\d*|\d{1,3}(,\d{3})*)(\.\d+)?\b

New

There are 1,000 people in those 3 towns.
1,000
3

There are 1,000 people in those 3 towns.
1,000
3