Regular Expressions 101

1st Alternative([3-9][0-9]{3}|2[1-9][0-9]{2}|20[3-9][0-9]|202[1-9])-[0-9]{2}-[0-9]{2}

Group 1([3-9][0-9]{3}|2[1-9][0-9]{2}|20[3-9][0-9]|202[1-9])

1st Alternative[3-9][0-9]{3}

Character Class[3-9]

3-9one character from 3 (51₁₀) to 9 (57₁₀)

Character Class[0-9]{3}

{3}matches exactly 3 characters from the set below:

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

2nd Alternative2[1-9][0-9]{2}

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[1-9]

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

Character Class[0-9]{2}

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

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

3rd Alternative20[3-9][0-9]

20the literal text 20

Character Class[3-9]

3-9one character from 3 (51₁₀) to 9 (57₁₀)

Character Class[0-9]

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

4th Alternative202[1-9]

202the literal text 202

Character Class[1-9]

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

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 - (45₁₀ / 55₈ / 2D₁₆)

Character Class[0-9]{2}

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

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

2nd Alternative2020-1[0-9]-[0-9]{2}

2020-1the literal text 2020-1

Character Class[0-9]

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

-the literal - (45₁₀ / 55₈ / 2D₁₆)

Character Class[0-9]{2}

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

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

3rd Alternative2020-09-2[2-9]

2020-09-2the literal text 2020-09-2

Character Class[2-9]

2-9one character from 2 (50₁₀) to 9 (57₁₀)

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.

Search reference

Regular Expression

([3-9][0-9]{3}|2[1-9][0-9]{2}|20[3-9][0-9]|202[1-9])-[0-9]{2}-[0-9]{2}|2020-1[0-9]-[0-9]{2}|2020-09-2[2-9]

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