Regular Expressions 101

^start of line

Group 1([0-9]{4})

Character Class[0-9]{4}

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

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

Group 2(\s*|\/|[-]|[.])

1st Alternative\s*

\s*any whitespace character, repeated any number of times

2nd Alternative\/

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

3rd Alternative[-]

Character Class[-]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

4th Alternative[.]

Character Class[.]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 3([0-1][0-9])

Character Class[0-1]

0-1one character from 0 (48₁₀) to 1 (49₁₀)

Character Class[0-9]

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

Group 4(\s*|\/|[-]|[.])

1st Alternative\s*

\s*any whitespace character, repeated any number of times

2nd Alternative\/

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

3rd Alternative[-]

Character Class[-]

-the literal - (45₁₀ / 55₈ / 2D₁₆)

4th Alternative[.]

Character Class[.]

.the literal . (46₁₀ / 56₈ / 2E₁₆)

Group 5([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)

$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.

Search reference

Regular Expression

^([0-9]{4})(\s*|\/|[-]|[.])([0-1][0-9])(\s*|\/|[-]|[.])([0-9]{2})$

Test String
New

January 14, 2018

2018/07/18
20180718
2018.07.18
2018-08-18
181007
20181202
201107
921109

13 กันยายน 2535

1ธันวาคม2561

1ธันวา2561

5 กันยา 61

1กันยา2501

1 September 2018

15October18

1/9/2018

10/3/2018

12/12/2018

4 กันยา 2018

12-12-18

12-9-2018

12Sep 2018

15มีนาคม 2018

15.Sep.2018

Regular Expression

Test StringNew

Test String
New