Check if Read-Host is a number for Switch - powershell

Question

I'm just learning switch to make my logic a bit cleaner, and it seems to work except I'm having trouble determining if my Read-Host value is a number (for the access point number to select).
## Give option to reset all aps on site
$continueVal = Read-Host "`nSpecify AP # to see more details or type 'Reset' to reset all APs in Store $Store"
## Start switch
$event = switch ($continueVal) {
[int]{
$apNumber = $continueVal
Query-AP($apNumber)
}
'Reset' {
Manage-Prelim($e = 2)
}
default {
Repeat
}
}
When I was using If/Else/ElseIf I'd use if($continueVal -gt 0) which would work, but still dirty. With switch it seems that -gt 0 is improper syntax and fails. How would I effectively check if the value of $continueVal is a number to pass it to the next function as $apNumber?
I don't want to pre-validate as possible options can come through as an integer or a string.

Answer 1

Here is another approach that uses parameters and parameter sets:
# testscript.ps1
[CmdletBinding(DefaultParameterSetName = "APNumber")]
param(
[Parameter(Mandatory = $true,ParameterSetName = "APNumber")]
[Int] $APNumber,
[Parameter(Mandatory = $true,ParameterSetName = "Controller")]
[String] $Controller,
[Parameter(Mandatory = $true,ParameterSetName = "Reset")]
[Switch] $Reset
)
switch ( $PSCmdlet.ParameterSetName ) {
"APNumber" {
"You specified -APNumber with value '$APNumber'"
break
}
"Controller" {
"You specified -Controller with value '$Controller'"
break
}
"Reset" {
"You specified -Reset"
break
}
}
This script is simple to use. Example usage:
testscript -APNumber 3
testscript -Controller "foo"
testscript -Reset
If you omit any parameters, it will prompt for the -APNumber parameter (since it specifies that as the default parameter set).

Answer 2

Now that I understand your question more, this can be done with switch -regex and parsing. Here is a short example:
do {
$response = Read-Host "Enter a response"
$valid = $true
switch -regex ( $response ) {
'^AP Number \d+$' {
$arg = [Regex]::Match($_,'\d+$').Value -as [Int]
Write-Host "You entered 'AP Number $arg'"
break
}
'^Controller \S+$' {
$arg = [Regex]::Match($_,'\S+$').Value
Write-Host "You entered 'Controller $arg'"
break
}
'^Reset$' {
Write-Host "You entered 'Reset'"
break
}
default {
$valid = $false
Write-Host "Invalid entry"
}
}
}
until ( $valid )
Note that this is more code than the parameter version, more complex, and you can't automate it.