Regular Expressions 101

Pro

^start of line

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

Non-Capturing Group(?:(?:\d|[1-9]\d|1[0-5]\d|16[0-7])(?:\.\d{1,2})?|168(?:\.0{1,2})?)

1st Alternative(?:\d|[1-9]\d|1[0-5]\d|16[0-7])(?:\.\d{1,2})?

Non-Capturing Group(?:\d|[1-9]\d|1[0-5]\d|16[0-7])

1st Alternative\d

\da digit

2nd Alternative[1-9]\d

Character Class[1-9]

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

\da digit

3rd Alternative1[0-5]\d

1the literal 1 (49₁₀ / 61₈ / 31₁₆)

Character Class[0-5]

0-5one character from 0 (48₁₀) to 5 (53₁₀)

\da digit

4th Alternative16[0-7]

16the literal text 16

Character Class[0-7]

0-7one character from 0 (48₁₀) to 7 (55₁₀)

Non-Capturing Group(?:\.\d{1,2})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

\d{1,2}a digit, repeated between 1 and 2 times

2nd Alternative168(?:\.0{1,2})?

168the literal text 168

Non-Capturing Group(?:\.0{1,2})?

?repeats the group contents below at most once:

\.the literal . (46₁₀ / 56₈ / 2E₁₆)

0{1,2}the literal 0 (48₁₀ / 60₈ / 30₁₆) , repeated between 1 and 2 times

Character Class[NS]?

?matches at most one character from the set below:

Nthe literal N (78₁₀ / 116₈ / 4E₁₆) (case sensitive)

Sthe literal S (83₁₀ / 123₈ / 53₁₆) (case sensitive)

$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

^\s*(?:(?:\d|[1-9]\d|1[0-5]\d|16[0-7])(?:\.\d{1,2})?|168(?:\.0{1,2})?)[NS]?$

New