PHP determines whether a string is all Chinese or contains Chinese characters

$str="'324 is";
if(!eregi("[^x80-xff]","$str")){
echo "All in Chinese";
 }else{
echo "not";
}

2, determine if it contains Chinese

$str = "Chinese";
if (preg_match("/[x7f-xff]/", $str)) {
echo "Contains Chinese";
}else{
 echo "No Chinese";
}
 or
$pattern = '/[^x00-x80]/';
if(preg_match($pattern,$str)){
echo "Contains Chinese";
}else{
 echo "No Chinese";
}

Instructions: The above code was tested under utf-8 and has not been tested under other encodings.