Retrieves the number of matched substrings (including substring 0,
that is the whole matched text), so 1 is returned if the pattern
has no substrings in it and 0 is returned if the match failed.
If the last match was obtained using the DFA algorithm, that is
using Regex.matchAll or Regex.matchAllFull, the retrieved
count is not that of the number of capturing parentheses but that of
the number of matched substrings.
Retrieves the number of matched substrings (including substring 0, that is the whole matched text), so 1 is returned if the pattern has no substrings in it and 0 is returned if the match failed.
If the last match was obtained using the DFA algorithm, that is using Regex.matchAll or Regex.matchAllFull, the retrieved count is not that of the number of capturing parentheses but that of the number of matched substrings.