Regular Expressions 101

Explanation

Pro

^start of string

Group 1(0[1-9]|1[0-9]|2[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 Alternative1[0-9]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-9]

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

3rd Alternative2[0-9]

2the literal 2 (50₁₀ / 62₈ / 32₁₆)

Character Class[0-9]

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

4th Alternative3[01]

3the literal 3 (51₁₀ / 63₈ / 33₁₆)

Character Class[01]

0the literal 0 (48₁₀ / 60₈ / 30₁₆)

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

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

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[0-2]

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-2]

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

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]{4}

{4}matches exactly 4 characters from the set below:

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

$end of string, or before its final line terminator

Global pattern flags

i modifier: insensitive. Matches without distinguishing uppercase and lowercase letters

g modifier: global. Finds all matches instead of stopping after the first

Match Information

Detailed match information will be displayed here automatically.

Quick Reference

25 tokens

Regular Expression

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

New

http://www.example.com
file://www.example.png
file://www.example.com
ftp://image.jpg
ftp:host..jpgcom
http://www.imgur.com/image2.gif
oops I made a mistake.jpg
htp://notamatch.html.jpg
http://website.com.jpg
this isn't even valid...jpg
jpg.jpg.com
file.com
file://.com
file://a.com
http://something.co.uk
http://something.cosuk

Extraction

http://www.example.com
file://www.example.png
file://www.example.com
ftp://image.jpg
ftp:host..jpgcom
http://www.imgur.com/image2.gif
oops I made a mistake.jpg
htp://notamatch.html.jpg
http://website.com.jpg
this isn't even valid...jpg
jpg.jpg.com
file.com
file://.com
file://a.com
http://something.co.uk
http://something.cosuk