如何移除PowerShell数组拼接结果末尾的逗号？

给你三种实用的修改方式，按需选择：

方法1：用数组收集后拼接（最推荐） #

PowerShell处理这类元素拼接时，最省心的方式是先把所有要拼接的内容存到数组里，最后用-join ', '统一连接，自动避免末尾多余逗号：

clear
$excludeList = 'choco*','kb*','dotnet*','netfx*','*.install*','*.portable*','vcredist*','packages*','lessmsi*'
$appsInstalled = Get-ChildItem -Exclude $excludeList -Recurse -Path "C:\ProgramData\chocolatey\lib\*.nuspec"

# 初始化数组存储每个应用的信息
$appList = @()
Foreach ($app in $appsInstalled) {
    [xml]$XmlDocument = Get-Content $app.Fullname
    $appInfo = "$($XmlDocument.package.metadata.Title) v$($XmlDocument.package.metadata.Version)"
    $appList += $appInfo
}
# 用逗号加空格连接数组元素
$dataOut = $appList -join ', '
$dataOut

方法2：直接移除末尾的逗号和空格 #

如果不想改动循环逻辑，直接在最后对$dataOut做修剪，去掉末尾的, 即可：

clear
$dataOut = ''
$excludeList = 'choco*','kb*','dotnet*','netfx*','*.install*','*.portable*','vcredist*','packages*','lessmsi*'
$appsInstalled = Get-ChildItem -Exclude $excludeList -Recurse -Path "C:\ProgramData\chocolatey\lib\*.nuspec"

Foreach ($app in $appsInstalled) {
    [xml]$XmlDocument = Get-Content $app.Fullname
    $appsInstalled = $XmlDocument.package.metadata.Title + " v" +$XmlDocument.package.metadata.Version + ", "
    $dataOut = $dataOut + $appsInstalled
}
# 移除末尾的逗号和空格
$dataOut = $dataOut.TrimEnd(', ')
$dataOut

方法3：循环内判断是否为最后一个元素 #

通过判断当前元素是不是集合里的最后一个，仅在非最后一个元素后添加逗号：

clear
$dataOut = ''
$excludeList = 'choco*','kb*','dotnet*','netfx*','*.install*','*.portable*','vcredist*','packages*','lessmsi*'
$appsInstalled = Get-ChildItem -Exclude $excludeList -Recurse -Path "C:\ProgramData\chocolatey\lib\*.nuspec"

$totalCount = $appsInstalled.Count
$currentIndex = 0
Foreach ($app in $appsInstalled) {
    $currentIndex++
    [xml]$XmlDocument = Get-Content $app.Fullname
    $appInfo = "$($XmlDocument.package.metadata.Title) v$($XmlDocument.package.metadata.Version)"
    # 仅非最后一个元素后添加逗号
    if ($currentIndex -lt $totalCount) {
        $appInfo += ', '
    }
    $dataOut += $appInfo
}
$dataOut

内容的提问来源于stack exchange，提问作者Darren