Note: Parameter flags was added in PHP 4 Beta 3.
Returns an array containing substrings of subject split along boundaries matched by pattern.
If limit is specified, then only substrings up to limit are returned, and if limit is -1, it actually means "no limit", which is useful for specifying the flags.
flags can be any combination of the following flags (combined with bitwise | operator):
If this flag is set, only non-empty pieces will be returned by preg_split().
If this flag is set, parenthesized expression in the delimiter pattern will be captured and returned as well. This flag was added for 4.0.5.
See also spliti(), split(), implode(), preg_match(), preg_match_all(), and preg_replace().