Regular Expressions 101

Explanation

Pro

^start of line

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

Character Class[0-9]{2}

{2}matches exactly 2 characters from the set below:

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

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

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

Group 3((0)[0-9])

Group 4(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])

Group 5((1)[0-2])

Group 6(1)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-2]

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

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 7([1-2](0|9)[0-9]{2})

Character Class[1-2]

1-2one character from 1 (49₁₀) to 2 (50₁₀)

Group 8(0|9)

1st Alternative0

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

2nd Alternative9

9the literal 9 (57₁₀ / 71₈ / 39₁₆)

Character Class[0-9]{2}

{2}matches exactly 2 characters from the set below:

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

$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

^([0-9]{2})\.(((0)[0-9])|((1)[0-2]))\.([1-2](0|9)[0-9]{2})$

New

// valid
01.12.2001
22.11.2000
22.01.1913

// not valid
22.22.2002
33.33.3333
22.13.2001
22.11.1812

// valid
01.12.2001
22.11.2000
22.01.1913

// not valid
22.22.2002
33.33.3333
22.13.2001
22.11.1812