store items in variable - Powershell

Hi All,

I have this line of code in my script:

if ($null -ne $ListView.SelectedItems) {
        $ListView.ItemsSource = @($ListView.SelectedItems | Select-Object DisplayName, TotalItemSize, ItemCount, Database, TotalDeletedItemSize,DeletedItemCount, LastLoggedOnUserAccount, LastLogonTime, LastLogoffTime -OutVariable $mailboxtomigrate)
		$m = $mailboxtomigrate | Out-String
		[System.Windows.MessageBox]::Show("$m")

the selected can be many. I need to store it in a variable so I can loop through it when I run the new-moverequest script.

so I need the display names to be stored as a string in the variable e.g. $mailboxtomigrate = "display name 1", "display name 2", "display name 3"

how do I do this?

is better if I out the results into an array?  how do I do this?

thank you in advance