^start of line
?matches at most one character from the set below:
-the literal - (4510 / 558 / 2D16)
+the literal + (4310 / 538 / 2B16)
\d+a digit, repeated at least once
\.?optionally matches the literal . (4610 / 568 / 2E16)
\d*a digit, repeated any number of times
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string
g modifier: global. Finds all matches instead of stopping after the first