Negative Lookbehind(?<!\d) Positive Lookahead(?=[\d. -]{11}(?!\d)) Character Class[\d. -]{11} {11}matches exactly 11 characters from the set below:
\da digit
.the literal . (4610 / 568 / 2E16)
the literal (3210 / 408 / 2016)
-the literal - (4510 / 558 / 2D16)
\d{1,}a digit, repeated at least once
.the literal . (4610 / 568 / 2E16)
the literal (3210 / 408 / 2016)
-the literal - (4510 / 558 / 2D16)
\d{1,}a digit, repeated at least once
\1the text saved by group 1
\d{1,}a digit, repeated at least once
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