Powershell call class on a string? - powershell

Question

Trying to call this class to reverse a string in powershell, but can't figure out how to call it.. very simple question but not sure how to do it
class Reverse{
[string]$Stringy
[string]Reversi(){
return $(this.Stringy[-1..-$Stringy.length] -join "")
}
}
Then i am not sure how to call this class. By itself, the return statement does the job, but i need to call the class, please help, no hints just point to the code there is no help online.

Answer 1

My poor attempt to answer this question, as Abraham pointed out in his comment, you need to create an instance of the class:
class ReverseClass {
[string]$Stringy
ReverseClass([string]$String){
$this.Stringy = $String
}
[string]Reverse(){
return -join $this.Stringy[-1..-$this.Length()]
}
[int]Length(){
return $this.Stringy.Length
}
}
$z = [ReverseClass]'Hello World!'
$z.Reverse() # => !dlroW olleH
Again, I insist, a class is an overkill for what you need to do:
function Reverse-String([string]$String){
-join $String[-1..-$String.Length]
}
Reverse-String 'Hello world!' # => !dlrow olleH
If this class was stored on a file like C:\users\user\my documents\script.ps1 and you wanted to load the class or function to your current session you would need to dot source it (simply add a dot before the path). This will load all everything, classes, functions, variables, etc to your current scope.
For example:
If your current directory is not where the script is stored:
. "C:\users\user\my documents\script.ps1"
If you changed directory to my documents in this case:
. .\script.ps1

Answer 2

Are you sure you need a class with an instance method?
If you change the method to be static instead, you can pass whatever string value as a method parameter and get your result without having to create an instance of the class:
class ReverseClass {
static [string] Reverse([string]$string){
return -join $string[-1..-$string.Length]
}
}
Now you can call it using the static member operator :::
PS ~> [ReverseClass]::Reverse("hello")
olleh

Answer 3

Continuing from my comment.
This...
class Reverse{
[string]$Stringy
[string]Reversi(){
return $(this.Stringy[-1..-$Stringy.length] -join "")
}
}
...is not a PowerShell function. This is how you declare a function in PowerShell.
<#
.Synopsis
Short description
.DESCRIPTION
Long description
.EXAMPLE
Example of how to use this
.EXAMPLE
Another example of how to use this
#>
function Verb-Noun
{
[CmdletBinding()]
[Alias()]
[OutputType([int])]
Param
(
[string]$Param1,
[int]$Param2
)
}
# calling the function
Verb-Noun -Param1 '' -Param2 ''
For strings, there is no reason to explicitly cast them as strings. Anything thing in quotes (single or double), is automatically seen as a string.
This is all documented in the PowerShell help files...
Get-Help -Name About_functions
... and MS Docs.
Though you can do classes in PowerShell v5 and higher. As documented in the Powershell help files...
Get-Help -Name About_classes
... and MS Docs.

Answer 4

class Reverse{
[string]$Stringy
[string]Reversi(){
return $this.Stringy[-1..-$this.Stringy.length] -join ""
}
}
PS C:> $reverse=New-Object Reverse -Property #{Stringy="Hello World"}
PS C:> $reverse.Reversi()
dlroW olleH