PREG_SET_ORDER

PREG_SET_ORDER is one of the accepted parameters for preg_match_all parameter #4 (optionally as a bitmask).

PREG constant: PREG_SET_ORDER — Orders results so that $matches[0] is an array of first set of matches, $matches[1] is an array of second set of matches, and so on. This flag is only used with preg_match_all.

PREG_SET_ORDER = 2;