Regular Expressions 101

Explanation

Pro

1st Alternative(\d{4}\-(0[1-9]|1[012])\-(0[1-9]|[12][0-9]|3[01]))

Group 1(\d{4}\-(0[1-9]|1[012])\-(0[1-9]|[12][0-9]|3[01]))

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

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

Group 2(0[1-9]|1[012])

1st Alternative0[1-9]

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 - (45₁₀ / 55₈ / 2D₁₆)

Group 3(0[1-9]|[12][0-9]|3[01])

1st Alternative0[1-9]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

Character Class[1-9]

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

2nd Alternative[12][0-9]

Character Class[12]

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 Alternative3[01]

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[01]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

2nd Alternative(\d{2}\-([Jj]an|[Ff]eb|[Mm]ar|[Aa]pr|[Mm]ay|[Jj]un|[Jj]ul|[Aa]ug|[Ss]ep|[Oo]ct|[Nn]ov|[Dd]ec)\-\d{4})

Group 4(\d{2}\-([Jj]an|[Ff]eb|[Mm]ar|[Aa]pr|[Mm]ay|[Jj]un|[Jj]ul|[Aa]ug|[Ss]ep|[Oo]ct|[Nn]ov|[Dd]ec)\-\d{4})

\d{2}a Unicode decimal digit, repeated exactly 2 times

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

1st Alternative[Jj]an

Character Class[Jj]

Jthe literal J (74₁₀ / 112₈ / 4A₁₆) (case sensitive)

jthe literal j (106₁₀ / 152₈ / 6A₁₆) (case sensitive)

anthe literal text an (case sensitive)

2nd Alternative[Ff]eb

Character Class[Ff]

Fthe literal F (70₁₀ / 106₈ / 46₁₆) (case sensitive)

fthe literal f (102₁₀ / 146₈ / 66₁₆) (case sensitive)

ebthe literal text eb (case sensitive)

3rd Alternative[Mm]ar

Character Class[Mm]

Mthe literal M (77₁₀ / 115₈ / 4D₁₆) (case sensitive)

mthe literal m (109₁₀ / 155₈ / 6D₁₆) (case sensitive)

arthe literal text ar (case sensitive)

4th Alternative[Aa]pr

Character Class[Aa]

prthe literal text pr (case sensitive)

5th Alternative[Mm]ay

6th Alternative[Jj]un

7th Alternative[Jj]ul

8th Alternative[Aa]ug

9th Alternative[Ss]ep

10th Alternative[Oo]ct

11th Alternative[Nn]ov

12th Alternative[Dd]ec

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

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

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

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

(\d{4}\-(0[1-9]|1[012])\-(0[1-9]|[12][0-9]|3[01]))|(\d{2}\-([Jj]an|[Ff]eb|[Mm]ar|[Aa]pr|[Mm]ay|[Jj]un|[Jj]ul|[Aa]ug|[Ss]ep|[Oo]ct|[Nn]ov|[Dd]ec)\-\d{4})

New

testing 2023-02-13  and even more testing 13-feb-2023

Substitution

testing 2023-02-13  and even more testing 13-feb-2023