PHP determines Chinese and English characters (one more)

I seem to remember that I posted one before, written by myself. Today’s one is online and comes from: http://www.cnblogs.com/zcy_soft/archive/2010/12/13/1904791.html

/* There is actually a lot of knowledge involved in judging Chinese. The underlying internal encoding involves various differences in utf-8, gbk, and gb13800. I once studied the problem of how to distinguish what character a character is. There are too many related details.

Today I made a PHP code to determine Chinese. I hope it can be helpful to friends who are studying Chinese judgment. */



 New Document
< ;META http-equiv="Content-Type" content="text/html; charset=utf-8">


$str = "China";
 echo $str;
echo "";
//if (preg_match("/^[".chr(0xa1)."-".chr(0xff)."]+$/", $str) ) { //Can only be used under GB2312
if (preg_match("/^[x7f-xff]+$/", $str)) { //Compatible with gb2312, utf-8
 echo "Correct input";
 } else {
 echo "Wrong input";
}
?>


/*
Encoding table
Double-byte character encoding range
1. GBK (GB2312/GB18030)
x00-xff GBK double-byte encoding range
x20-x7f ASCII
xa1-xff Chinese gb2312
x80-xff Chinese gbk
2. UTF-8 (Unicode)
u4e00-u9fa5 (Chinese)
x3130-x318F (Korean
 xAC00-xD7A3 (Korean)
u0800-u4e00 (Japanese)*/