Regular Expressions 101

Explanation

Pro

^start of string

Group 1([1-9]{1}|(0[0-9]|1[0-2]))

1st Alternative[1-9]{1}

Character Class[1-9]{1}

{1}matches one character from the set below:

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

2nd Alternative(0[0-9]|1[0-2])

Group 2(0[0-9]|1[0-2])

1st Alternative0[0-9]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[0-9]

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

2nd Alternative1[0-2]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-2]

0-2one character from 0 (48₁₀) to 2 (50₁₀)

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Group 3([1-9]{1}|0[1-9]|1\d|2\d|3[01])

1st Alternative[1-9]{1}

Character Class[1-9]{1}

{1}matches one character from the set below:

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

2nd Alternative0[1-9]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

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

3rd Alternative1\d

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

\da digit

4th Alternative2\d

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

\da digit

5th Alternative3[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)

\d{4}a digit, repeated exactly 4 times

$end of string

Unit Test Summary

Ready to run

Quick Reference

26 tokens

Regular Expression

^([1-9]{1}|(0[0-9]|1[0-2]))\/([1-9]{1}|0[1-9]|1\d|2\d|3[01])\/\d{4}$

Regular Expression

Unit Tests