AD user creation with SamAccountName availability check loop - powershell

Question

I'm learning Powershell by making a script that will hopefully automate everything that needs to be done when we get a new hire or a consultant. Currently I'm working on the part that will create the AD account. Below are the variables specific to this portion of the script.
#Variables for preliminary SamAccountName, modifiers and initials array
$PrelSamAccountName = ("se" + [string]$GivenName.Substring(0,3) + [string]$SurName.Substring(0,3)).ToLower()
$Modifier1 = 1
$Modifier2 = 0
$InitialsArray = #("x","y","z")
Here is the loop. I cut out a bunch of parameters on New-ADUser to make it less cluttered.
try {
#Checks if preliminary SamAccountName is taken or not
$ADCheck = Get-ADUser -Filter {SamAccountName -eq $PrelSamAccountName}
#Creates new user
New-ADUser -Name $Name -SamAccountName $PrelSamAccountName
} catch {
#Replaces final character in preliminary SamAccountName with "1++"
while (($ADCheck | Select-Object -ExpandProperty SamAccountName) -eq $PrelSamAccountName) {
$PrelSamAccountName = ([string]$PrelSamAccountName.Substring(0,7) + ($Modifier1++)).ToLower()
}
#Changes $Initials from $null to x/y/z if an existing user has identical name as new user
while (($ADCheck | Select-Object -ExpandProperty Name) -eq $Name) {
$Initials = $InitialsArray[$Modifier2++]
$Name = $GivenName + " " + $Initials + " " + $SurName
}
}
Everything is working as intended, except for the fact that a new user is created every other time I run the loop. Ideally I would want it to create a new user every time it is run. :)
I'm assuming it has something to do with the placement of the $ADCheck variable, but after having rewritten this portion multiple times I simply can't get it to work. Any ideas?
Thanks in advance.

Answer 1

You have some logical problems in here:
Follow this Approach:
Pseudocode:
while (user exist) {create new username}
new-aduser new username
PS Code:
function new-sam
{
#creates new sam
}
$sam = "username"
$a=$false
while (!$a)
{
try {
$a = [bool](Get-ADUser -Identity $sam )
}
catch {
$a = $false; $sam = new-sam
}
}
new-aduser ....