Regular Expressions 101

Pro

^start of line

Group 1((?!0(\.0{1,3})?$)[0-4](\.\d{1,3})?|5(\.0{1,3})?)

1st Alternative(?!0(\.0{1,3})?$)[0-4](\.\d{1,3})?

Negative Lookahead(?!0(\.0{1,3})?$)

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Group 2(\.0{1,3})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

0{1,3}the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated between 1 and 3 times

$end of line

Character Class[0-4]

0-4one character from 0 (48₁₀) to 4 (52₁₀)

Group 3(\.\d{1,3})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

2nd Alternative5(\.0{1,3})?

5the literal 5 (53₁₀ / 65₈ / 35₁₆)

Group 4(\.0{1,3})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

0{1,3}the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated between 1 and 3 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.

26 tokens

^((?!0(\.0{1,3})?$)[0-4](\.\d{1,3})?|5(\.0{1,3})?)$

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