title: Powershell: Selecting parts of an array with WHERE
body: <p>I have two arrays $list_CloudUsers and $list_Active. Both have a column called Alias.
  I want to filter $list_CloudUsers  so that the list does not have any of the ALIASes that are contained in $list_Active.</p>
  <p>I was able to do it with:</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>$list_arc = Import-CSV $Arc_LastAccess
  $list_Active =  $list_arc | Where { [int]$_.InactivityDays -le 30}
  
  $NewList = @()
  ForEach ($User_Cloud in $list_CloudUsers)
          {
          $Alias = $User_Cloud.Alias
          if ($list_Active -match $alias) {continue}
          $NewList += $User_Cloud
          }</code></pre>
  </div>
  </div>
  </p>
  <p>But it does not work with this. Any ideas how I can get the WHERE to work correctly.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>$list_arc = Import-CSV $Arc_LastAccess
  $list_Active =  $list_arc | Where { [int]$_.InactivityDays -le 30}
  $NewList1 = $list_CloudUsers | Where {$list_Active -NotMatch $_.alias}</code></pre>
  </div>
  </div>
  </p>