A piece of PHP code that cannot output Chinese characters. please provide solutions

A piece of PHP code that cannot output Chinese characters can be solved. & lt ;? Php & nbsp; header (& quot; Expires: Mon, 26Jul199705: 00: 00GMT & quot;); & nbsp; header (& quot; cache-C: a piece of PHP code that cannot output Chinese characters. please solve it.
Header ("Expires: Mon, 26 Jul 1997 05:00:00 GMT ");
Header ("Cache-Control: no-cache, must-revalidate ");
Header ("Pragma: no-cache ");
Include ("connect. php ");
Ini_set ("date. timezone", "Asia/Shanghai ");
$ D1 = date ("Y-m-d ");
$ Query = mysql_query ("select * from item where status <> 'done 'Order by date desc ");
While ($ now = mysql_fetch_array ($ query )){
$ User =" ";
$ User. =" ";
$ User. = $ now ['Serial'];
$ User. =" ";
$ User. =" ";
$ User. = $ now ['name'];
$ User. =" ";
$ User. =" ";
$ User. = $ now ['dep'];
$ User. =" ";
$ User. =" ";
$ Usera = round (-strtotime ($ d1) + strtotime ($ now ['completetime'])/3600/24 );
If ($ usera <0 ){
$ Us = "expired:" + abs ($ usera );
}
If ($ usera> = 0) & ($ usera <= 3 )){
$ Us = "coming soon:" + abs ($ usera );
}
If ($ usera> 3 ){
$ Us = "and:" + abs ($ usera );
}
$ User. = "expired" + $ us;
$ User. =" ";
$ User. =" ";
$ User. = $ now ['status'];
$ User. =" ";
$ User. =" ";
$ User. = $ now ['percent '];
$ User. =" ";
$ User. =" ";
$ User. = $ now ['creator'];
$ User. =" ";
$ User. =" ";
$ User. = $ now ['Date'];
$ User. =" ";
$ User. =" ";
Echo $ user;
}
?>


If ($ usera <0 ){
$ Us = "expired:" + abs ($ usera );
}
If ($ usera> = 0) & ($ usera <= 3 )){
$ Us = "coming soon:" + abs ($ usera );
}
If ($ usera> 3 ){
$ Us = "and:" + abs ($ usera );
}
$ User. = "expired" + $ us;
Why can't I output only the numbers of $ us and the Chinese characters above it: the expiration date is about to expire, and so on?

------ Solution --------------------
This is not js, and the string connection should use. instead of +
Modify all the errors in the file as follows:

$ Us = "coming soon:" + abs ($ usera );

Modify

$ Us = "about to expire:". abs ($ usera );


------ Solution --------------------
This is related to type conversion. + The operator is an arithmetic task, and the result is forcibly converted to a floating point or integer. the preceding string naturally does not exist. Php.net manual describes type conversion.
Use "expiration date:". abs ($ usera );