Powershell script error adding integers

Question

Hi All, I am trying to add integers but the script is not running. I am using variable "a" with the same line of thinking as
$arg in $args
$a in $as
#  create a script thats adds numbers using foreach
# put an if statement if the numbers are not valid
My script begins here:
   set-psdebug -strict
    $total = 0
foreach($a in $as)
               if ( $a -as[int] -eq $null)
            { Write-host "this is not a valid number"
                exit 1
                $total += $a
              Write-host "The total is $total"
I am calling my script with the following line: .\finalexam\foreachadd.ps1 6 6 i
The error is :
The variable '$as' cannot be retrieved because it has not been set.
At C:\cmd.practise\finalexam\foreachadd.ps1:8 char:15
+ foreach($a in $as)
+               ~~~
    + CategoryInfo          : InvalidOperation: (as:String) [], RuntimeException
    + FullyQualifiedErrorId : VariableIsUndefined
Thank-you
SQL 75
(LearningPowerhsell)

Answer 1

You need to go back and study the very initial basics of PowerShell.  You are repeatedly guessing wrong and misunderstanding how this works. Without the fundamentals you will be forever lost.
Try to understand why and how the following works.  Read the basics of using PowerShell variables and loops.
$as=1,2,'x',4,5,'z'
$total=0
foreach($a in $as){
if($a -as [int]){
        $total+=$a
}else{
        Write-host "$a cannot be converted to a valid integer 32"
Write-host "The total is $total"
You also need to learn how to format your code.  Tat would make it easier for you too see your mistakes.
\_(ツ)_/