$$wname

w变量名为变量，减少重复代码。

 <?php
 function w_w($w_arr, $link)
 {
     $wres = true;
     foreach ($w_arr AS $w) {
         $wname = 'w' . $w;
         js_pure_alert($wname);
         if (!empty($$wname)) {
             $sql = 'UPDATE asin_email SET email_type=' . $w . ' WHERE id IN(' . substr($$wname, 0, strlen($$wname) - 1) . ')';
             if (!mysqli_query($link, $sql)) $wres = false;
         }
     }
     return $wres;
 }