Powershell中笨拙的函数-如何使其简洁？

我刚刚在Powershell中编写了一个简单的函数

Function Get-Stage
{       
    $myEnv = Get-Environment
    $devEnvs = "D","Dev","Test","T"
    $prodEnvs = "P","U","PTA","B"
    if($devEnvs -contains $myEnv)
    {
        return "D"
    }
    elseif($prodEnvs -contains $myEnv)
    {
        return "P"          
    }
}

编辑

Get-Environment

是一个读取注册表以查找环境文本的函数，该文本可以是

$devEnvs

和

$prodEnvs

中列出的任何字符串值。函数将根据从获取环境返回的内容返回

D

或

P

---

我不喜欢它。有没有一种好的、可读的、简洁的编写方法，你能想到吗？

好吧，关于更好地编写代码的方法的问题在很大程度上是基于不同的观点，但是你可以做如下事情：

function Get-Stage
{
    $environment = Get-Environment

    switch ($environment)
    {
        {$PSItem -in "D","Dev","Test","T"}{
            Write-Output "D"
        }
        {$PSItem -in "P","U","PTA","B"}{
            Write-Output "P" 
        }
        default{
            Write-Error "Invalid environment value in registry ('$PSItem')"
        }
    }
}

switch ($environment)
{
    {"D","Dev","Test","T" -contains $_}{
        Write-Output "D"
    }
    {"P","U","PTA","B" -contains $_}{
        Write-Output "P" 
    }
    default{
        Write-Error "Invalid environment value in registry ('$_')"
    }
} 

如果要支持PowerShell v2，只需将switch语句更改为以下内容：

function Get-Stage
{
    $environment = Get-Environment

    switch ($environment)
    {
        {$PSItem -in "D","Dev","Test","T"}{
            Write-Output "D"
        }
        {$PSItem -in "P","U","PTA","B"}{
            Write-Output "P" 
        }
        default{
            Write-Error "Invalid environment value in registry ('$PSItem')"
        }
    }
}

switch ($environment)
{
    {"D","Dev","Test","T" -contains $_}{
        Write-Output "D"
    }
    {"P","U","PTA","B" -contains $_}{
        Write-Output "P" 
    }
    default{
        Write-Error "Invalid environment value in registry ('$_')"
    }
} 

---

好的，关于更好地编写代码的方法的问题在很大程度上是基于不同的观点，但是您可以做如下事情：

function Get-Stage
{
    $environment = Get-Environment

    switch ($environment)
    {
        {$PSItem -in "D","Dev","Test","T"}{
            Write-Output "D"
        }
        {$PSItem -in "P","U","PTA","B"}{
            Write-Output "P" 
        }
        default{
            Write-Error "Invalid environment value in registry ('$PSItem')"
        }
    }
}

switch ($environment)
{
    {"D","Dev","Test","T" -contains $_}{
        Write-Output "D"
    }
    {"P","U","PTA","B" -contains $_}{
        Write-Output "P" 
    }
    default{
        Write-Error "Invalid environment value in registry ('$_')"
    }
} 

如果要支持PowerShell v2，只需将switch语句更改为以下内容：

function Get-Stage
{
    $environment = Get-Environment

    switch ($environment)
    {
        {$PSItem -in "D","Dev","Test","T"}{
            Write-Output "D"
        }
        {$PSItem -in "P","U","PTA","B"}{
            Write-Output "P" 
        }
        default{
            Write-Error "Invalid environment value in registry ('$PSItem')"
        }
    }
}

switch ($environment)
{
    {"D","Dev","Test","T" -contains $_}{
        Write-Output "D"
    }
    {"P","U","PTA","B" -contains $_}{
        Write-Output "P" 
    }
    default{
        Write-Error "Invalid environment value in registry ('$_')"
    }
} 

---

这有什么好处吗

Function Get-Stage
{       
  $myEnv = Get-Environment;

  $envDict = @{
     "D" = @("Dev","Test","T");
     "P" = @("U","PTA","B")
  };

  $envDict.Keys | foreach {
    $envs = @($_) + $dict[$_];
    if($envs -contains $myenv) { return $_; }
  }
}

---

这有什么好处吗

Function Get-Stage
{       
  $myEnv = Get-Environment;

  $envDict = @{
     "D" = @("Dev","Test","T");
     "P" = @("U","PTA","B")
  };

  $envDict.Keys | foreach {
    $envs = @($_) + $dict[$_];
    if($envs -contains $myenv) { return $_; }
  }
}

---

你能解释一下这个功能的用途吗？

Get-Environment

做什么？你期望从这个函数中得到什么输入和输出？Get Environment在做什么？我已经更新了这个问题。你能解释一下这个函数的用途吗？

Get-Environment

做什么？您希望此函数有哪些输入和输出？Get Environment在做什么？我已经更新了问题Robert我使用的是powershell 2，我想此解决方案无法与此配合使用$PSItem是v3以后的版本，对吗？更新了我的答案，包括对v2的支持。但是，如果您想支持动态列表加载，请查看@neolik.Robert建议的解决方案。我使用的是powershell 2，我想这个解决方案不适用于此$PSItem是v3以后的版本，对吗？更新了我的答案，包括对v2的支持。但是，如果您想支持动态列表加载，请查看@neolik建议的解决方案。实际上，该解决方案看起来有点难以阅读。也许我的简单解决方案并没有那么糟糕。@MooMinTroll:不过，它应该更易于维护。没有任何东西的重复——代码或数据。您只需扩展其中的

$envDict

，它甚至可以是一个XML文件，因此维护它的人不需要了解Powershell。实际上，它看起来更难阅读。也许我的简单解决方案并没有那么糟糕。@MooMinTroll:不过，它应该更易于维护。没有任何东西的重复——代码或数据。您只需要扩展部分，其中显示

$envDict

，甚至可以是XML文件，因此维护它的人不需要了解Powershell。