string for matches to
pattern, then replaces the matched text
replacement and returns the result
string or FALSE on error. Multibyte character can be used in
Matching condition can be set by
parameter. If i is specified for this
parameter, the case will be ignored. If x is
specified, white space will be ignored. If m
is specified, match will be executed in multiline mode and line
break will be included in '.'. If p is
specified, match will be executed in POSIX mode, line break
will be considered as normal character. If e
replacement string will be
evaluated as PHP expression.
The internal encoding or the character encoding specified in mb_regex_encoding() will be used as character encoding.