将哈希表作为参数传递给 PowerShell 中的函数 [英] Passing a hashtable as an argument to a function in PowerShell

问题描述

我在 PowerShell 脚本中遇到问题:

I have a problem in a PowerShell script:

当我想将一个哈希表传递给一个函数时，这个哈希表不被识别为一个哈希表.

When I want to pass a Hashtable to a function, this hashtable is not recognized as a hashtable.

function getLength(){
    param(
        [hashtable]$input
    )

    $input.Length | Write-Output
}

$table = @{};

$obj = New-Object PSObject;$obj | Add-Member NoteProperty Size 2895 | Add-Member NoteProperty Count 5124587
$table["Test"] = $obj


$table.GetType() | Write-Output ` Hashtable
$tx_table = getLength $table `Unable to convert System.Collections.ArrayList+ArrayListEnumeratorSimple in System.Collections.Hashtable

为什么?

推荐答案

$Input 是一个 自动变量 枚举给定的输入.

$Input is an automatic variable that enumerates the input given.

选择任何其他变量名称，它就会起作用 - 尽管不一定如您所愿 - 要获取哈希表中的条目数，您需要检查 Count 属性:

Chose any other variable name and it'll work - although not necessarily as you might expect - to get the number of entries in a hashtable you need to inspect the Count property:

function Get-Length {
    param(
        [hashtable]$Table
    )

    $Table.Count
}

Write-Output 当您保持 $Table.Count 原样时隐含.

Write-Output is implied when you just leave the $Table.Count as is.

此外，当您使用 Param() 内联声明参数时，函数名称中的 () 后缀是不必要的语法糖，其含义为零 - 删除它

Also, the () suffix in the function name is unnecessary syntactic sugar with zero meaning when you declare your parameters inline with Param() - drop it

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