Report Active Directory Accounts that are Synchronized with Azure AD

Once we got that out of the way, here's the code that Kevin wrote more than two lines, but probably ten times faster, using Microsoft Graph and achieving the same thing in less time.

Connect-MgGraph -Scopes "User.Read.All"

$AzureUsers = Get-MgUser -All -Property 'OnPremisesSyncEnabled', 'DisplayName', 'UserPrincipalName','Id','Mail'
$Users = Get-ADUser -Filter "Enabled -eq '$True'" -Properties *

$CacheAzure = [ordered] @{}
foreach ($User in $AzureUsers) {
    $CacheAzure[$User.UserPrincipalName] = $User
}
$AllUsers = foreach ($User in $Users) {
    if ($CacheAzure[$User.UserPrincipalName]) {
        if ($CacheAzure[$User.UserPrincipalName].OnPremisesSyncEnabled) {
            $Synchronized = $true
        } else {
            $Synchronized = $false
        }
    } else {
        $Synchronized = $false
    }
    [PSCustomObject] @{
        DisplayName       = $User.DisplayName
        SamAccountName    = $User.SamAccountName
        UserPrincipalName = $User.UserPrincipalName
        LastLogonDate     = $User.LastLogonDate
        AzureADSynced     = $Synchronized
    }
}
$AllUsers | Format-Table -AutoSize