PHP multi-file compression function

function zip_files(string $zipName,...$files){
  //检测压缩包名称是否正确
  $zipExt=strtolower(pathinfo($zipName,PATHINFO_EXTENSION));
  if('zip'!==$zipExt){
    return false;
  }
  $zip=new ZipArchive();
  if($zip->open($zipName,ZipArchive::CREATE|ZipArchive::OVERWRITE)){
    foreach($files as $file){
      if(is_file($file)){
        $zip->addFile($file);
      }
    }
    $zip->close();
    return true;
  }else{
    return false;
  }
}