如何使这段代码组织得更好

Question

这是代码...我的 if , else 语句很长...如何将其分开？有什么建议吗？谢谢。

public function receiveMsg(aMsg){
    if($aMsg instanceof LoginMsg){
         $this->callingSomeMethod();         //should I separate this code into other class/ object? 
         $this->callingAnotherMethod();  //should I separate this code into other class/ object? 

         $aMsg = new RespondLoginMsg();  //should I separate this code into other class/ object? 
         $this->sendMsg($aMsg);          //should I separate this code into other class/ object? 

    }else if(aMsg instanceof LogoutMsg){
         $this->callingSomeMethod();     //should I separate this code into another class/ object? 

         $aMsg = new RespondLogoutMsg();     //should I separate this code into another class/ object? 
         $this->sendMsg($aMsg);               //should I separate this code into another class/ object? 


    }else if/*****bababab***/

    /*****many else if here (up to 200 msg+ , just upload 2 here.)***/


}

Answer 1

也许 switch 更容易阅读？ sendMsg 可以以任何一种方式移出，只需使用您在 swtich/if 中设置的 $aMsg 对象即可。

$strMessageClass=get_class($aMsg);
switch ($strMessageClass) {
    case 'LoginMsg':
        $this->callingSomeMethod();
        $aMsg = new RespondLoginMsg();
    case 'RespondLogoutMsg':
        $this->callingAnotherMethod();
        $aMsg = RespondLogoutMsg();
    default:
        // If you have any..
}
$this->sendMsg($aMsg);

Answer 2

如果需要的话，我不认为长 if/else 语句有什么根本错误。

如果您发现它有碍观瞻，为什么不将每个 if/else 块的内容定义为它自己的函数呢？

您还可以考虑消除冗余。如果它们都以 then 结尾

     $aMsg = new RespondLoginMsg();
     $this->sendMsg($aMsg);

，则无需在每个块中重复它。

Answer 3

除了摆脱过多的间距和换行符之外，我不明白这里的问题是什么。您需要检查多少个不同的类来检查某个项目是否是其实例？在我看来，这里的列表非常有限。如果您没有超过 3 或 4 个 if/else 语句，则只需将其保留为 if/else 即可。否则使用开关或循环。

您能更具体地说明您想要实现的目标吗？

这是代码的稍微干净的版本。

public function receiveMsg(aMsg) {
  if ($aMsg instanceof LoginMsg) {
    $this->callingSomeMethod(); 
    $this->callingAnotherMethod();

    $aMsg = new RespondLoginMsg();
    $this->sendMsg($aMsg);
  }
  else if (aMsg instanceof LogoutMsg) {
    $this->callingSomeMethod(); 

    $aMsg = new RespondLogoutMsg();
    $this->sendMsg($aMsg);
  }
  else if { /*****bababab***/

  }
  /*****many else if here***/
}