Regular Expressions 101

Explanation

Pro

^start of line

Non-Capturing Group(?:\d{4})?

?repeats the group contents below at most once:

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

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Non-Capturing Group(?:(?:\d\d)?\/){2}

{2}repeats the group contents below exactly 2 times:

Non-Capturing Group(?:\d\d)?

?repeats the group contents below at most once:

\da digit

\/the literal / (47₁₀ / 57₈ / 2F₁₆)

Non-Capturing Group(?:[A-Za-z\s-]+)?

?repeats the group contents below at most once:

Character Class[A-Za-z\s-]+

+matches at least one character from the set below:

A-Zone character from A (65₁₀) to Z (90₁₀) (case sensitive)

a-zone character from a (97₁₀) to z (122₁₀) (case sensitive)

\sany whitespace character

-the literal - (45₁₀ / 55₈ / 2D₁₆)

$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.

26 tokens

^(?:\d{4})?\/(?:(?:\d\d)?\/){2}(?:[A-Za-z\s-]+)?$

New

2020/06/25/XYZConf
2020///XYZConf
2020//25/XYZConf
2020/06//XYZConf
//25/XYZConf
///