将哈希表作为参数传递给PowerShell中的函数

I have a problem in a PowerShell script:

我在PowerShell脚本中遇到问题:

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

当我想将Hashtable传递给函数时,此哈希表不会被识别为哈希表。

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

Why?

2 个解决方案

#1

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

$ Input是一个自动变量,用于枚举给定的输入。

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:

选择任何其他变量名称,它将起作用 - 尽管不一定如您所料 - 要获取散列表中的条目数,您需要检查Count属性:

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

    $Table.Count
}

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

当您只保留$ Table.Count时,隐含写入输出。

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

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,意义为零 - 删除它

#2

I'm not really sure what to comment here, it seems self-explanatory. If not, leave a comment and I'll clarify.

我不太确定在这里发表什么评论,这似乎是不言自明的。如果没有,请发表评论,我会澄清。

$ExampleHashTable = @{
    "one" = "the loneliest number"
    "two" = "just as bad as one"
}

Function PassingAHashtableToAFunctionTest {
    param(
        [hashtable] $PassedHashTable,
        [string] $AHashTableElement
    )

    Write-Host "One is ... " 
    Write-Host $PassedHashTable["one"]
    Write-Host "Two is ... " 
    Write-Host $AHashTableElement
}

PassingAHashtableToAFunctionTest -PassedHashTable $ExampleHashTable `
    -AHashTableElement $ExampleHashTable["two"]

Output:

One is ... 
the loneliest number
Two is ... 
just as bad as one

#1