title: PowerShell append objects to variable list
body: <p>Fairly new to PowerShell and wanting to learn how to append objects to a variable list. Below is the error message:</p>
  <pre><code>Method invocation failed because [System.IO.FileInfo] does not contain a method named 'op_Addition'.
  At C:\Users\Username\Desktop\Sandbox\New folder\BoxProjectFiles.ps1:117 char:4
  +             $MechDWGFile += $file
  +             ~~~~~~~~~~~~~~~~~~~~~
      + CategoryInfo          : InvalidOperation: (op_Addition:String) [], RuntimeException
      + FullyQualifiedErrorId : MethodNotFound
  </code></pre>
  <p>and code:</p>
  <pre><code>LogWrite &quot;`n-------------Mechanical Drawing(s)------------&quot;
  foreach ($file in $MechDWGList)
  {
      # Where the file name contains one of these filters
      foreach($filter in $MechDWGFilterList)
      {
          if($file.Name -like $filter)
          {
              $MechDWGFile += $file # this is where the error is happening, so I know it is probably something simple
              LogWrite $file.FullName
          }
      }
  }
  </code></pre>
  <p>PowerShell 5.1 and Windows 10 OS is being used.</p>
  <p>Could someone help me understand what's wrong with my syntax?</p>