Regular Expressions 101

^start of line

-?optionally matches the literal - (45₁₀ / 55₈ / 2D₁₆)

Positive Lookahead(?=(?:\d\.?){1,8}$)

Non-Capturing Group(?:\d\.?){1,8}

{1,8}repeats the group contents below between 1 and 8 times:

\da digit

\.?optionally matches the literal . (46₁₀ / 56₈ / 2E₁₆)

$end of line

\d*a digit, repeated any number of times

Non-Capturing Group(?:\.\d{1,2})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d{1,2}a digit, repeated between 1 and 2 times

$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.

Search reference

Regular Expression

^-?(?=(?:\d\.?){1,8}$)\d*(?:\.\d{1,2})?$

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