title: How do I merge two "lists" in PowerShell when one list might be just one item from Get-Item?
body: <p>I am using Get-ChildItem to fetch locally installed certs. Then I'd like to delete these certs from my local certificate store. If I execute the script below it will work when there is more than one item returned in both the Get-ChildItem queries. But if only one item is returned in either of the queries the addition of the two collections will fail. Simply because with only one object returned the implementation only returns one instance and not a collection of one. What is the right approach here? I won't know if the result(s) returned from my queries will result in 0, 1 or multiple certs.</p>
  
  <pre><code>$myCerts = Get-ChildItem cert:\CurrentUser\My | Where-Object { $_.Subject -like "CN=$certName" }
  $trustedPeopleCerts = Get-ChildItem cert:\CurrentUser\TrustedPeople | Where-Object { $_.Subject -like "CN=$certName" }
  
  $allCerts = $myCerts + $trustedPeopleCerts
  
  foreach ($cert in $allCerts) {
      $store = Get-Item $cert.PSParentPath
      $store.Open('ReadWrite')
      $store.Remove($cert)
      $store.Close()
  }
  </code></pre>