how to use a FOR loop variable to help define another variable

Question

I am new to powershell scripts and not sure how to achieve the below:

$finalArray = @()
$tempArray0 = 'A'
$tempArray1 = 'B'
$tempArray2 = 'C'
FOR (i=0; i -eq 5; i++) {$finalArray += $tempArray[i]}

$finalArray

Output Should be:

A
B
C

Answer 1

If the variable name is itself variable, you'll have to use the Get-Variable cmdlet to retrieve its value:

$finalArray = @()
$tempArray0 = 'A'
$tempArray1 = 'B'
$tempArray2 = 'C'

for($i=0; $i -le 2; $i++) {
    $finalArray += (Get-Variable "temparray$i" -ValueOnly)
}

$finalArray

If you want to create variables with variable names, use the New-Variable cmdlet:

$Values = 'A','B','C'
for($i = 0; $i -lt $Values.Count; $i++){
    New-Variable -Name "tempvalue$i" -Value $Values[$i]
}

which would result in:

PS C:\> $tempvalue1
B

---

Although the above will solve the example you've presented, I can think of very few cases where you wouldn't be better of using a [hashtable] instead of variable variable names - they're usually an over-complication, and you'll end up with unnecessary code anyways because you need to calculate the variable names at least twice (during creation and again when reading the value).

From the comments, it sounds like you're trying to generate input for a password generator. This can be simplified grossly, without resorting to variable variable names:

# Create a hashtable and generate the characters 
$CharArrays = @{
    Letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToCharArray()
    Numbers = 0..9
}

# Generate some letters for the  password
$PasswordChars = $CharArrays['Letters'] |Get-Random -Count 10

# Generate a few digits
$PasswordChars += $CharArrays['Numbers'] |Get-Random -Count 4

# Shuffle them around a bit
$PasswordChars = $PasswordChars |Sort-Object {Get-Random}

# Create your password
$Password = $PasswordChars -join ''