PHP编码样式返回;开关/外壳 [英] PHP Coding styles return; in switch/case

问题描述

我们正在为我们的团队实施新的编码风格指南，php codesniffer在没有发现break时在switch case语句上打印警告，例如：

  switch（$ foo）{
 case 1：
 return 1; 
 case 2：
 return 2; 
默认值：
 return 3; 
} 
  

有什么好的理由使用：

  switch（$ foo）{
 case 1：
 return 1; 
 break; 
} 
  

c> c> 从开关返回。

但是对于每个 case 添加显式 break 作为防御性程序设计练习。

 开关（$ foo）{
 case 1：
 return 1; 
 break; 
 
 case 2：
 return 2; 
 break; 
} 
  

这个想法是，如果你以后更改你的代码 case 1 并删除return语句，您可能会忘记添加 break 。

这将意外导致程序流向情况2 。

  switch（$ foo）{
 case 1：
 somethingDifferent（）; 
 
 case 2：
 return 2; 
 break; 
} 
  

通过case语句稍有不同，您应该向代码添加注释

  switch（$ foo）{
 case 1：
 somethingDifferentAndWeWantToDoCase2AsWell（）; 
 //下降
 
情况2：
 return 2; 
 break; 
} 
  

与许多防御性编程做法一样，您必须平衡代码膨胀 - 这可能会杂乱你的代码，使其更少的可读性 - 值得或不。

we're trying to implement new coding style guidelines for our team, the php codesniffer is printing an warning on switch case statements when no "break" is found like:

switch ($foo) {   
    case 1:
      return 1;   
    case 2:
      return 2;   
   default:
       return 3; 
}

is there any good reason to use :

   switch ($foo) {
       case 1:
         return 1;
         break;
   }

?? the break is never reached ?

解决方案

It's perfectly valid to leave out the break when you return from a switch.

But it's fairly common practise to add explicit breaks to every case as a defensive programming practise.

switch ($foo) {
    case 1:
        return 1;
        break;

    case 2:
        return 2;
        break;
}

The idea is that should you later change your code in case 1 and remove the return statement, you could forget to add a break.

That would accidentally cause program flow to fall through to case 2.

switch ($foo) {
    case 1:
        somethingDifferent();

    case 2:
        return 2;
        break;
}

Falling through case statements is slightly unusual and you should add a comment to your code when you do it to show that it's intentional.

switch ($foo) {
    case 1:
        somethingDifferentAndWeWantToDoCase2AsWell();
        // fallthrough

    case 2:
        return 2;
        break;
}

As with many defensive programming practises you've got to balance whether the code bloat - which potentially clutters your code and make it less readable - is worth it or not.

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