Returns the end position of the match in the string. An integer can be specified for numeric groups or a string for named groups. Returns -1 if that group wasn't found or doesn't exist. Defaults to 0 (whole pattern). Returns the number of numeric capturing groups. Returns an array of names of named capturing groups. Returns the starting position of the match in the string. An integer can be specified for numeric groups or a string for named groups. Returns -1 if that group wasn't found or doesn't exist. Defaults to 0 (whole pattern). Returns the result of the match in the string. An integer can be specified for numeric groups or a string for named groups. Returns -1 if that group wasn't found or doesn't exist. Defaults to 0 (whole pattern).