class Person {
    [string] $FirstName
    [string] $LastName
    [string] Greeting() {
        return "Greetings, {0} {1}!" -f $this.FirstName, $this.LastName
    }
}

$x = [Person]::new()
$x.FirstName = "Jane"
$x.LastName = "Doe"
$greeting = $x.Greeting() # "Greetings, Jane Doe!"