Regular Expressions 101

Pro

^start of line

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

1st Alternative(?:(?:0)[0-9])

Non-Capturing Group(?:(?:0)[0-9])

Non-Capturing Group(?:0)

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[0-9]

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

2nd Alternative(?:(?:1)[0-2])

Non-Capturing Group(?:(?:1)[0-2])

Non-Capturing Group(?:1)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-2]

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

3rd Alternative(?:(?:[1-9]))

Non-Capturing Group(?:(?:[1-9]))

Non-Capturing Group(?:[1-9])

Character Class[1-9]

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

Non-Capturing Group(?:\/|\\)

1st Alternative\/

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

2nd Alternative\\

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

Group 2(\d{4})

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

25 tokens

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

New

12/02/2020
02/2020

12/02/2020
02/2020