Regular Expressions 101

Explanation
Pro

^start of line

\$the literal $ (36₁₀ / 44₈ / 24₁₆)

Character Class[1-9]

1-9one character from 1 (49₁₀) to 9 (57₁₀)

\d{0,2}a digit, repeated between 0 and 2 times

Non-Capturing Group(?:\,\d{3})?

?repeats the group contents below at most once:

\,the literal , (44₁₀ / 54₈ / 2C₁₆)

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

Non-Capturing Group(?:\.\d{2})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d{2}a digit, repeated exactly 2 times

Group 1([^,.\d$]|$)

1st Alternative[^,.\d$]

Negated Character Class[^,.\d$]

,the literal , (44₁₀ / 54₈ / 2C₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

$the literal $ (36₁₀ / 44₈ / 24₁₆)

2nd Alternative$

$end of line

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

^\$[1-9]\d{0,2}(?:\,\d{3})?(?:\.\d{2})?([^,.\d$]|$)

New

$100,000.4
$1.00
$999,999.99
$1


$999,999.999
$999,9999.99
$9999,999.99