list 从 Powershell 的列表中选择最后一项
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Pick last item from list in Powershell
提问by Nimjox
I'm trying to map a drive letter using this line of code which will give me a list of drives available from d to z.
我正在尝试使用这行代码来映射一个驱动器号，这将为我提供从 d 到 z 可用的驱动器列表。
ls function:[d-z]: -n|?{!(test-path $_)}
I'd like to then pick the last letter, not random, from the list. How would I go about doing that? New to Powershell, thanks for the help.
然后我想从列表中选择最后一个字母，而不是随机的。我该怎么做？Powershell 新手，感谢您的帮助。
回答by Joey
You can use Select-Object -Last 1at the end of that pipeline.
您可以Select-Object -Last 1在该管道的末尾使用。
回答by Dreami
If you look for a much more verbose, but (in my opinion) readable-improved version:
如果您寻找更冗长但（在我看来）可读性改进的版本：
# Get all drives which are used (unavailable)
# Filter for the "Name" property ==> Drive letter
$Drives = (Get-PSDrive -PSProvider FileSystem).Name
# Create an array of D to Z
# Haven't found a more elegant version...
$Letters = [char[]]([char]'D'..[char]'Z')
# Filter out, which $Letters are not in $Drives (<=)
# Again, filter for their letter
$Available = (Compare-Object -ReferenceObject $Letters -DifferenceObject $Drives | Where {$_.SideIndicator -eq "<="}).InputObject
# Get the last letter
$LastLetter = $Available[-1]
回答by Dave Sexton
Try this:
尝试这个：
ls function:[d-z]: -n|?{!(test-path $_)} | Select-Object -Last 1
回答by neontapir
Another option that doesn't require trying all paths from D-Z is to parse Get-Psdrive. Here's an example:
另一个不需要从 DZ 尝试所有路径的选项是解析Get-Psdrive. 下面是一个例子：
$lettersInUse = Get-Psdrive | ? { $_.Name.Length -eq 1 } | % { $_.Name }
$lastDriveLetter = [Char]'Z'
while ($lettersInUse -contains $lastDriveLetter) {
$lastDriveLetter = [Char]($lastDriveLetter - 1)
}
$lastDriveLetter
回答by Ashu
In case of Array
$newArray = @(git tag --list)
$lastmember = $newArray[$newArray.Count – 1]In case you have list
$newArray | Select-Object -Last 1
在数组的情况下
$newArray = @(git tag --list)
$lastmember = $newArray[$newArray.Count – 1]如果您有列表
$newArray | 选择对象 - 最后 1
