需要在powershell中的arraylist中添加和查找元素索引值吗？(Need to add and find element index value in arraylist in power

需要在powershell中的arraylist中添加和查找元素索引值吗？(Need to add and find element index value in arraylist in powershell?)

在arraylist中添加字符串元素并找到它的索引值？

[code...] $eventList = New-Object System.Collections.ArrayList $eventList.Add("Hello") $eventList.Add("test") $eventList.Add("hi")

不工作投掷错误： -

Method invocation failed because [System.String[]] doesn't contain a method named 'Add'. At C:\Users\Administrator\Desktop\qwedqwe.ps1:9 char:15 + $eventList.Add <<<< ("Hello") + CategoryInfo : InvalidOperation: (Add:String) [], RuntimeException + FullyQualifiedErrorId : MethodNotFound

add string element in arraylist and find it's index value?

[code...] $eventList = New-Object System.Collections.ArrayList $eventList.Add("Hello") $eventList.Add("test") $eventList.Add("hi")

Not working throwing error:-

Method invocation failed because [System.String[]] doesn't contain a method named 'Add'. At C:\Users\Administrator\Desktop\qwedqwe.ps1:9 char:15 + $eventList.Add <<<< ("Hello") + CategoryInfo : InvalidOperation: (Add:String) [], RuntimeException + FullyQualifiedErrorId : MethodNotFound

最满意答案

正如评论中所提到的，如果你在ISE（或其他IDE）中开发它并且之前$eventList使用类型转换分配了$eventList ，如下所示：

[string[]]$eventList = @()

或类似的，注释掉前面的行将无法帮助你 - 变量已经存在，并且在其生命周期的剩余时间内将该类型绑定到该变量。

您可以使用Remove-Variable eventList删除任何先前的分配

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一旦你对它进行了排序，我们就可以继续实际定位索引了。 如果您对完全匹配的索引感兴趣，请使用IndexOf() ：

PS> $eventList.IndexOf('hi') 2

如果这不够灵活，请使用实现FindIndex() 的通用List<T> 。

FindIndex()接受一个谓词 - 一个根据输入（列表中的项）返回$true或$false的函数：

$eventList = New-Object System.Collections.Generic.List[string] $eventList.Add("Hello") $eventList.Add("test") $eventList.Add("hi") $predicate = { param([string]$s) return $s -like 'h*' }

然后使用$predicate函数作为唯一参数调用FindIndex() ：

PS> $eventList.FindIndex($predicate) 0

（它在索引0处匹配Hello ，因为它以h开头）

As mentioned in the comments, if you've developing this in ISE (or another IDE) and previously assigned $eventList with a type cast, like so:

[string[]]$eventList = @()

or similar, commenting out previous lines won't help you - the variable already exists and will have that type bound to it for the remainder of its lifetime.

You can remove any previous assignments with Remove-Variable eventList

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Once you've got that sorted, we can move on to actually locating the index. If you're interested in the index of an exact match, use IndexOf():

PS> $eventList.IndexOf('hi') 2

If that isn't flexible enough, use the a generic List<T>, which implements FindIndex().

FindIndex() takes a predicate - a function that returns $true or $false based on input (the items in the list):

$eventList = New-Object System.Collections.Generic.List[string] $eventList.Add("Hello") $eventList.Add("test") $eventList.Add("hi") $predicate = { param([string]$s) return $s -like 'h*' }

And then call FindIndex() with the $predicate function as the only argument:

PS> $eventList.FindIndex($predicate) 0

(it matches Hello at index 0 because it starts with an h)