/**
* Convert a string to an array
* @param string $str
* @param number $split_length
* @return multitype:string
*/
function
mb_str_split(
$str
,
$split_length
=1,
$charset
=
"UTF-8"
){
if
(func_num_args()==1){
return
preg_split(
'/(?<!^)(?!$)/u'
,
$str
);
}
if
(
$split_length
<1)
return
false;
$len
= mb_strlen(
$str
,
$charset
);
$arr
=
array
();
for
(
$i
=0;
$i
<
$len
;
$i
+=
$split_length
){
$s
= mb_substr(
$str
,
$i
,
$split_length
,
$charset
);
$arr
[] =
$s
;
}
return
$arr
;
}