Regular Expressions 101

^start of string

Group 1([1-9]|([012][0-9])|(3[01]))

1st Alternative[1-9]

Character Class[1-9]

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

2nd Alternative([012][0-9])

Group 2([012][0-9])

Character Class[012]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

3rd Alternative(3[01])

Group 3(3[01])

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[01]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 4([0]{0,1}[1-9]|1[012])

1st Alternative[0]{0,1}[1-9]

Character Class[0]{0,1}

{0,1}matches at most one character from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

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

2nd Alternative1[012]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[012]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

\da digit

the literal (32₁₀ / 40₈ / 20₁₆)

Character Class[012]{0,1}

{0,1}matches at most one character from the set below:

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

:the literal : (58₁₀ / 72₈ / 3A₁₆)

Character Class[0-6]

0-6one character from 0 (48₁₀) to 6 (54₁₀)

Character Class[0-9]

0-9one character from 0 (48₁₀) to 9 (57₁₀)

$end of string, or before its final line terminator

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

No unit tests · Add a test to get started

Search reference

Regular Expression

^([1-9]|([012][0-9])|(3[01]))\/([0]{0,1}[1-9]|1[012])\/\d\d\d\d [012]{0,1}[0-9]:[0-6][0-9]$

Unit Tests

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