convert Office 365 powershell array to string with commas

Question

I am trying to add users to an Office 365 group via powershell as described here -

https://technet.microsoft.com/en-us/library/mt238269(v=exchg.160).aspx

I am able to add single or multiple users using the Add-UnifiedGroupLinks command however I am sourcing a list of users I want to add in from an Office 365 security group and it brings back the users in an array which the command Add-UnifiedGroupLinks doesnt seem to like

    #add the Office 365 security group group to the O365 group
    $groupid = "TestGroup" #Office 365 security Group
    $alias = "Office365 Group" #office 365 group
    $sg = Get-MsolGroup | where-object { $_.DisplayName -eq "$groupid"} #Get the group
    $sgemails = Get-MsolGroupMember -GroupObjectId $sg.ObjectId | Select EmailAddress   #Get the email addresses   
    $sgemails # Show the users
    Add-UnifiedGroupLinks –Identity $alias -LinkType Members -links $sgemails # Add the users to the Group

Is there a way to convert this array which comes out like

EmailAddresses
user1@test.com
user2@test.com
user3@test.com

to a a string so it is user1@test.com, user2@test.com, user3@test.com

For reference this is the error when you try to run the powershell script

PS U:\>         Add-UnifiedGroupLinks –Identity $alias -LinkType Members -links $sgemails 
Cannot process argument transformation on parameter 'Links'. 
Cannot convert value "System.Collections.ArrayList" to type  "Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter[]". 
Error: "Cannot convert value  "@{EmailAddress=user1@test.com}" to type "Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter". 
Error: "Cannot convert hashtable to an object of the following type:  Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter. 
Hashtable-to-Object conversion is not supported in restricted  language mode or a Data section.""
    + CategoryInfo          : InvalidData: (:) [Add-UnifiedGroupLinks], ParameterBindin...mationException
    + FullyQualifiedErrorId : ParameterArgumentTransformationError,Add-UnifiedGroupLinks
    + PSComputerName        : outlook.office365.com

• You would be able to test the above script by just setting the $groupid to a security group in your Office 365 environment and $alias to a O365 group.

Thanks

Answer 1

Sounds to me like the $sgemails is still in an array, which it doesn't know what to do with. Let's try to convert it to a string. Change Line 6 (second to last line) to:

$sgemailString = [string]::Join(",",$sgemails)
Add-UnifiedGroupLinks –Identity $alias -LinkType Members -links $sgemailString # Add the users to the Group