问题描述
编写PowerShell脚本，以多维（3维）数组中第二维度的值进行过滤，并打印出结果
#三维数组源数据
“A”, “11”, “Cheng Du”
“B”, “21”, “Chong Qing”
“C”, “31”, “Shang Hai”
“D”, “41”, “Bei Jing”
“E”, “51”, “Nan Jing”
#从地址中过滤以Chong开头的地区, 结果需要为
B, 21, Chong Qing
PowerShell脚本为：
$CityList = [System.Collections.ArrayList]::new()
$CityList.Add(@(“A”,“11”,“Cheng Du”)) | Out-Null
$CityList.Add(@(“B”,“21”,“Chong Qing”)) | Out-Null
$CityList.Add(@(“C”,“31”,“Shang Hai”)) | Out-Null
$CityList.Add(@(“D”,“41”,“Bei Jing”)) | Out-Null
$CityList.Add(@(“E”,“51”,“Nan Jing”)) | Out-Null
Write-Host "==== 开始过滤 Chong ==== " -ForegroundColor DarkYellow
$FinalCityList = $CityList | Where-object -filterScript {$_[2] -like "Chong*"}
Write-Host "Final City List 类型" -ForegroundColor Green
$FinalCityList.GetType()
Write-Host "Final City 数量为: " $FinalCityList.Count -ForegroundColor Green
Write-Host ""
Write-Host "==== 循环打印List中所有元素结果 ==== " -ForegroundColor DarkYellow
foreach( $aaa in $FinalCityList)
{
Write-Host $aaa[0]','$aaa[1]','$aaa[2]
}
Write-Host ""
Write-Host "==== 直接输出对象的结果 ==== " -ForegroundColor red
$FinalCityList
输出结果 ：当过滤结果大于1时，显示正常，当过滤结果为1时，结果显示异常。结果变成了一个一位数组，Count结果为3。
image.png
这是为什么呢？
问题分析
从 $FinalCityList 的打印结果分析，当 Where-Object 查看到结果只有一个的时候，就把结果对象进行了多维到一维的转换。所以结果变为了一个包含三行内容的一位数组。
image.png
问题解决
$FinalCityList = @($CityList | Where-object -filterScript {$_[2] -like "Chong*"})
把 Where-Object 方法用 @() 进行对象转换即可。
image.png
完整的PowerShell脚本为：
$CityList = [System.Collections.ArrayList]::new()
$CityList.Add(@(“A”,“11”,“Cheng Du”)) | Out-Null
$CityList.Add(@(“B”,“21”,“Chong Qing”)) | Out-Null
$CityList.Add(@(“C”,“31”,“Shang Hai”)) | Out-Null
$CityList.Add(@(“D”,“41”,“Bei Jing”)) | Out-Null
$CityList.Add(@(“E”,“51”,“Nan Jing”)) | Out-Null
foreach( $ccc in $CityList)
{
Write-Host $ccc[0]','$ccc[1]','$ccc[2]
}
Write-Host "==== 开始过滤 CityList 中包含 Chong 的城市 ==== " -ForegroundColor Yellow
$FinalCityList = @($CityList | Where-object -filterScript {$_[2] -like "Chong*"})
Write-Host "Final City List 类型" -ForegroundColor Green
$FinalCityList.GetType()
Write-Host "Final City 数量为: " $FinalCityList.Count -ForegroundColor Green
Write-Host ""
Write-Host "==== 循环打印List中所有元素结果 ==== " -ForegroundColor DarkYellow
foreach( $aaa in $FinalCityList)
{
Write-Host $aaa[0]','$aaa[1]','$aaa[2]
}
Write-Host ""
Write-Host "==== 直接输出对象的结果 ==== " -ForegroundColor red
$FinalCityList
参考文档
What does the "@" symbol do in PowerShell?：https://stackoverflow.com/questions/363884/what-does-the-symbol-do-in-powershell
当在复杂的环境中面临问题，格物之道需：浊而静之徐清，安以动之徐生。 云中，恰是如此!
