Проверка на наличие пустых полей

$objSearcher = New-Object System.DirectoryServices.DirectorySearcher
$objSearcher.SearchRoot = "LDAP://OU=xxx,DC=xxx,DC=ru"
$objSearcher.Filter = "(&(objectCategory=person)(!userAccountControl:1.2.840.113556.1.4.803:=2))"
$users = $objSearcher.FindAll()
$users.Count
$users | ForEach-Object {
   $user = $_.Properties
   New-Object PsObject -Property @{
   ФИО = [string]$user.cn
   Отдел = [string]$user.department
   Login = [string]$user.samaccountname 
   }
} | Export-Csv -NoClobber -Encoding utf8 -Path  d:\user.csv

if ($user.cn -ne "" -and $user.department -ne "" -and $user.samaccountname -ne "") {
New-Object PsObject -Property @{
ФИО = [string]$user.cn
Отдел = [string]$user.department
Login = [string]$user.samaccountname 
}
}

$users|?{$_.cn -ne "" -and $_.department -ne "" -and $_.samaccountname -ne ""}|Foreach-object{}...

 if ($LoginText.Text -ne '' -and $LoginText.Text -ne $NULL -and $PasswordText.Text -ne '' -and $PasswordText.Text -ne $NULL) {
      $login = $LoginText.Text
      $password = $PasswordText.Text  
    }

@('', $null, " ", 0, 1).Where{$_}.foreach{"[$_]"}

!0
!$null
!""
!" "
!1
![datetime]::Now

function check-password ( $login, $password, $strength, $target )
{
 
    class passwd {
        
        [bool] $valid = $false;
        [int] $strength = 0
        [string] $target
        [int] Validate() {$false}
    }
 
    $p = New-Object passwd
 
    $p.Validate()
 
    $p      
       
}
 
$result = check-password ( $LoginText.Text, $PasswordText.Text, 2 );
$result.valid ? "Нормально" : "Уходи, ты лишний здесь";

[bool]($null) -eq [bool]("")

$null -eq ""

$null -eq $qweruioiuytrewertyuioiuytrewawseyu

[string]::IsNullOrEmpty('')
[string]::IsNullOrWhiteSpace('')

($a, "", 0, "a").Where{!$_}.foreach{
    "do something"
}

-not $a
-not ""
-not 0
-not "a"