Powershell - persist variable outside of function - powershell

Question

I'm trying to import an xml file and store as a variable for the remainder of a powershell session. The import is obviously successful but the variable content does not persist outside of the function.
Function auth
{
$cred = import-clixml -Path c:\temp\cred.xml
}

Answer 1

try this:
Function auth
{
$global:cred = "test"
}
auth
$global:cred

Answer 2

You can use globals as Esperento57 suggests or you can do this
function auth
{
return 'test'
}
$cred = auth
More succinct:
function auth
{
'test'
}
$cred = auth

Answer 3

You need to declare the variable outside the scope of the function first and then inside the function explicitly tell the variable to update using the script:var method.
Here's the example is taken from https://www.kongsli.net/2013/04/25/powershell-gotchas-refer-to-variables-outside-a-function/ to which credit is given.
The thing is that we have to explicitly tell Powershell to update the variable in the parent scope instead of creating a new variable in the current scope.
$x = 1
function changeit {
"Changing `$x. Was: $x"
$script:x = 2
"New value: $x"
}
"`$x has value $x"
changeit
"`$x has value $x"

Answer 4

If you need to do this but with a number of functions and variables, you can place them all into a script and then dotsource the script.
Imagine a script like this:
#MyDevFunctions.ps1
$myImportantVar = "somevar"
$myOtherVar = "ABC123"
Function Get-MyCoolValue(){$myImportantVar}
Write-Host "Finished Loading MyDevFunctions"
If you wanted to run this, and then also persist the values of the variables and also the functions themselves, from your parent script you simply invoke it like so:
PS > . .\MyDevFunctions.ps1
"Finished Loading MyDevFunctions"
PS > $myOtherVar
ABC123
PS> Get-MyCoolValue
someVar