powershell mandatory parameter with default value shown

Question

I am looking for a way to have an PowerShell script ask for an parameter which needs to be mandatory, but shown with an default value, e.g.:

    .\psscript
    Supply values for the following parameters:
    parameter1[default value]:
    parameter2[1234]:

I want to ask for input but provide some default values.

If I use the mandatory option it asks for the values nicely but doesn't show the default value or process the given value. If I don't make it mandatory then PowerShell doesn't ask for the value at all.

Here's some script examples I tried:

    [CmdletBinding()]
    Param(
        [parameter(Mandatory=$true)] $SqlServiceAccount = $env:computername + "_sa",
        [parameter(Mandatory=$true)] $SqlServiceAccountPwd
    )

This script asks for parameters but does not show or process the default value if I just press enter on the first parameter.

    [CmdletBinding()]
    Param(
        [parameter(Mandatory=$false)] $SqlServiceAccount = $env:computername + "_sa",
        [parameter(Mandatory=$true)] $SqlServiceAccountPwd
    )

This script doesn't ask for the first parameter, but processes the default value.

Answer 1

Here's a short example that might help:

    [CmdletBinding()]
    Param(
        $SqlServiceAccount = (Read-Host -prompt "SqlServiceAccount ($($env:computername + "_sa"))"),
        $SqlServiceAccountPwd = (Read-Host -prompt "SqlServiceAccountPwd")
    )
    if (!$SqlServiceAccount) { $SqlServiceAccount = $env:Computername + "_sa" }
    ...