stri_escape_unicode(str)
\a
, \b
, \t
, \n
, \v
,
\f
, \r
, "
, '
, \\
or either {\uXXXX} (4 hex digits) or {\UXXXXXXXX} (8 hex
digits) otherwise.As usual, any input string is converted to Unicode before executing the escape process.
stri_unescape_unicode