Loading two arrays from a CSV - arrays

Question

I have a CSV File that has two columns Employee and Manager and I would like to import them into two Variables for use later in my script. However when I run my code it only captures the last data item in the CSV as the previous one is being over written.
$CSVFiles = Import-CSV "C:\T2\EmployeeManager.csv"
ForEach($CSVFile in $CSVFiles)
{
$Employee = ($CSVFile.Employee); $Manager = ($CSVFile.Manager)
}

Answer 1

$Employee = $CSVFiles | Select -Expand Employee
$Manager = $CSVFiles | Select -Expand Manager

Answer 2

That's because you are overwriting the added data each time the loop runs. IN PowerShell the += appends to an object. Try this -
$Employee = #()
$Manager = #()
$CSVFiles = Import-CSV "C:\T2\EmployeeManager.csv"
ForEach($CSVFile in $CSVFiles)
{
$Employee += $CSVFile.Employee; $Manager += $CSVFile.Manager
}

Answer 3

Vivek Kumar Singh's helpful answer explains the problem with your approach well and offers a solution.
Here's a simpler alternative (PSv3+), given that you're loading the entire CSV file into (custom objects) into memory anyway:
$CSV = Import-CSV "C:\T2\Employee.csv"
$Employees = $CSV.Employee # collect the Employee column values across all input rows
$Managers = $CSV.Manager # ditto for Manager
This approach takes advantage of the PSv3+ member-access enumeration feature.
In PSv2, use iRon's helpful solution.
Comparing the performance of the solutions:
The member-enumeration solution in this answer is fastest,
followed by iRon's Select -Expand solution
with Vivek's foreach loop being the slowest by far, not least because use of += to (conceptually) extend an array requires creating a new instance behind the scenes in every iteration.

Answer 4

This ended up being my final coding to accomplish my end goal. I want to thank all the posters I used a little learning from all of you to come to the solution I wanted.
$EmployeeLists = #()
$ManagerLists = #()
$Employees = #()
$Managers = #()
$CSVFiles = Import-CSV "C:\T2\EmployeeManager.csv"
ForEach($CSVFile in $CSVFiles)
{
$EmployeeLists += ($CSVFile.Employee)
}
ForEach($CSVFile in $CSVFiles)
{
$ManagerLists += ($CSVFile.Manager)
}
$Employees += ForEach ($EmployeeList in $EmployeeLists) { Get-ADUser -Properties * -Filter { DisplayName -like $EmployeeList } | Select SamAccountName -ExpandProperty SamAccountName }
$Managers += ForEach ($ManagerList in $ManagerLists) { Get-ADUser -Properties * -Filter { DisplayName -like $ManagerList } | Select SamAccountName -ExpandProperty SamAccountName }
$EmployeeLists
"`n`n`n"
$Employees