Regular Expressions 101

Pro

^start of line

Negative Lookahead(?!0)

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

\d{1,4}a digit, repeated between 1 and 4 times

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

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\da digit

\d?optionally matches a digit

$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

^(?!0)\d{1,4}(?:\.\d\d?)?$

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