php 区分中文，英文，中英混合

             $str1="是你";
             $strA = trim($str1);
             $lenA = strlen($strA);
             $lenB = mb_strlen($strA,"utf-8");
             if($lenA===$lenB){
                 echo "英文";
             }else{
                 if($lenA % $lenB == 0){
                     echo "中文";
                   }else{
                     echo  "中英";
                   }
             }