Password generator by PowerShell

New-Password.ps1

param([switch]$Upper, [switch]$Lower, [switch]$Number, [int]$Length = 8)
function Make-CharArray($FirstChar, $LastChar)
{
	$FirstIndex = [char]::ConvertToUtf32($FirstChar, 0)
	$LastIndex = [char]::ConvertToUtf32($LastChar, 0)
	$Chars = $FirstIndex..$LastIndex | ForEach-Object { [char]::ConvertFromUtf32($_) }
	return $Chars
}

$UpperChars = Make-CharArray 'A' 'Z'
$LowerChars = Make-CharArray 'a' 'z'
$NumberChars = Make-CharArray '0' '9'
if (!($Upper -or $Lower -or $Number))
{
	$Upper = $Lower = $Number = $True
}
$Chars = @()
if ($Upper) { $Chars = $Chars + $UpperChars }
if ($Lower) { $Chars = $Chars + $LowerChars }
if ($Number) { $Chars = $Chars + $NumberChars }
$Random = New-Object Random
[string]::Concat((1..$Length | ForEach-Object { $Chars[$Random.Next(0, $Chars.Length - 1)] }))