How To Create An Array Reading from Host?

Question

I am creating a script that will allow batch creation of new users but am running into an issue with the creation of the array.

$fname = @()
$lname = @()

$i = 0

$fname[$i] = Read-Host "`nWhat is the first name of the new user?"
$fname[$i] = $fname[$i].trim()
$lname[$i] = Read-Host "What is the last name of the new user?"
$lname[$i] = $lname[$i].trim()

If I run this I get the error:

Index was outside the bounds of the array.
At line:1 char:1
+ $fname[$i] = Read-Host "`nWhat is the first name of the new user?"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (:) [], IndexOutOfRangeException
    + FullyQualifiedErrorId : System.IndexOutOfRangeException

Method invocation failed because [System.Object[]] does not contain a method named 'trim'.
At line:2 char:13
+             $fname[$i] = $fname.trim()
+             ~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound

Answer 1

You are creating an array with an fixed size of zero. As $fname[0] doesn't exist in the array you can't change it's value. One solution would be to use += to add an element to your existing array:

$fname = @()
$lname = @()

$i = 0

$fname += Read-Host "`nWhat is the first name of the new user?"
$fname[$i] = $fname[$i].trim()
$lname += Read-Host "What is the last name of the new user?"
$lname[$i] = $lname[$i].trim()

As a side note, I personally wouldn't use different arrays for my user information but instead create PSCustomObject:

$UserTable = @()

$obj = New-Object psobject
$obj | Add-Member -MemberType NoteProperty -Name FirstName -Value (Read-Host "`nWhat is the first name of the new user?").Trim()
$obj | Add-Member -MemberType NoteProperty -Name LastName -Value (Read-Host "What is the last name of the new user?").Trim()

$UserTable += $obj

$i = 0

$UserTable[$i].FirstName
$UserTable[$i].LastName