I’m writing a an Azure Function App in PowerShell to manage Exchange Online User’s Mailbox settings. (no Not available vs MS Graph)
I’m looking to see what Members of a Group there are. When I issue the Command

$getDistListOutput = Get-DistributionGroupMember  @getDistListparms |   Where-Object {$_.alias -ne $SelfIdentity} | Select-Object Identity 

I can get one of three types of results in $getDistListOutput, Null, One user or Multiple users. When I take the output $getDistListOutput and convert it to JSON and add to the Existing JSON structure I get one of the three situations:

//No GroupMember

{
  "ForwardingAddressID": "{"Identity":"smtp:[email protected]"}",
  "GroupMembers": null
}

//Single GroupMember

{
  "ForwardingAddressID": "{"Identity":"smtp:[email protected]"}",
  "GroupMembers": "{"Identity":"smtp:[email protected]"}",
}

//Multiple GroupMembers

{
  "ForwardingAddressID": "{"Identity":"smtp:[email protected]"}",
  "GroupMembers": ["{"Identity":"smtp:[email protected]"}","{"Identity":"smtp:[email protected]"}"]
}

No I’m trying to map the data returned into C# Classes. The following works for the ForwardingAddressID though I can’t seem to come up with the proper way to get the GroupMembers decoded with its 3 variants.

           ExchPS_GetUserMailData_Reply getUserMailDataReplyDeserialized = JsonConvert.DeserializeObject<ExchPS_GetUserMailData_Reply>(AzureResponseDeserialized.OutputData);
                
           if (!(string.IsNullOrWhiteSpace(getUserMailDataReplyDeserialized.ForwardingAddressID)))
           {
               ExchPS_UserIdentity_Data forwardingAddressIDSerializedReply = JsonConvert.DeserializeObject<ExchPS_UserIdentity_Data>(getUserMailDataReplyDeserialized.ForwardingAddressID);

               if ((forwardingAddressIDSerializedReply != null) )
               {
                   if (forwardingAddressIDSerializedReply.Identity != null)
                   {
                       ForwardMbx = true;
                       ForwardMbxTo = forwardingAddressIDSerializedReply.Identity;
                   }
                   else
                   {
                       ForwardMbx = false;
                       ForwardMbxTo = "";
                   }
               }

           }

If there is nothing in the value set for GroupMembers, don’t do anything.
If there is a [ as the First, it’s an Array.
If there is a { as the First, it’s a single.

if (!(string.IsNullOrWhiteSpace(getUserMailDataReplyDeserialized.GroupMembers)))
{
    if (getUserMailDataReplyDeserialized.GroupMembers[0] == '[')
    {
        ExchPS_GroupMembers_Reply[] getGroupMembersSerializedReply = JsonConvert.DeserializeObject<ExchPS_GroupMembers_Reply[]>(getUserMailDataReplyDeserialized.GroupMembers);
        if ((getGroupMembersSerializedReply != null))
        {
            if (getGroupMembersSerializedReply.First != null)
            {
                ForwardMbx = true;
                //ForwardMbxTo = getGroupMembersSerializedReply.Identity[0].Identity;
            }
            else
            {
                ForwardMbx = false;
            }
        } 
    } else if (getUserMailDataReplyDeserialized.GroupMembers[0] == '{')
    {
        ExchPS_UserIdentity_Data getGroupMembersSerializedReply = JsonConvert.DeserializeObject<ExchPS_UserIdentity_Data>(getUserMailDataReplyDeserialized.GroupMembers);
        if (getGroupMembersSerializedReply != null)
        {
            if (getGroupMembersSerializedReply.Identity != null)
            {
                ForwardMbx = true;
                ForwardMbxTo = getGroupMembersSerializedReply.Identity;
            }
            else
            {
                ForwardMbx = false;
            }
        }
    }
}

Classes defined:

// Single User Identity
class ExchPS_UserIdentity_Data
{
    [JsonProperty(nameof(Identity))]
    public string Identity { get; set; } = string.Empty;
}

// Array of User Identities
[JsonArray]
class ExchPS_GroupMembers_Reply
{
    [JsonProperty(nameof(Identity))]
    public string Identity { get; set; } = string.Empty;
}


class ExchPS_GetUserMailData_Reply
{
    [JsonProperty(nameof(GroupMembers))]
    public string GroupMembers { get; set; } = string.Empty;

    [JsonProperty(nameof(ForwardingAddressID))]
    public string ForwardingAddressID { get; set; } = string.Empty;
}