Check if a string is not NULL or EMPTY
if (-not ([string]::IsNullOrEmpty($version)))
{
$request += "/" + $version
}
You can also use !
as an alternative to -not
.
You don't necessarily have to use the [string]:: prefix. This works in the same way:
if ($version)
{
$request += "/" + $version
}
A variable that is null or empty string evaluates to false.
As in many other programming and scripting languages you can do so by adding !
in front of the condition
if (![string]::IsNullOrEmpty($version))
{
$request += "/" + $version
}
If the variable is a parameter then you could use advanced function parameter binding like below to validate not null or empty:
[CmdletBinding()]
Param (
[parameter(mandatory=$true)]
[ValidateNotNullOrEmpty()]
[string]$Version
)
I would define $Version as a string to start with
[string]$Version
and if it's a param you can use the code posted by Samselvaprabu or if you would rather not present your users with an error you can do something like
while (-not($version)){
$version = Read-Host "Enter the version ya fool!"
}
$request += "/" + $version