CODEWITHSUNDEEP
powershellpiping
amarnath chatterjee
amarnath chatterjee

Reputation: 1962

Powershell input piping issue

I am not able to run this simple powershell program

[int]$st1 = $input[0]
[int]$st2 = $input[1]
[int]$st3 = $input[2]
[int]$pm = $input[3]
[int]$cm = $input[4]

$MedMarks = $st1 + $st2 + $st3 - ($pm + $cm)
Write-Host "Med Marks  $MedMarks"

I am trying to run it with input pipeline like this

120, 130, 90, 45, 30 | .\sample_program.ps1

I am consistently getting this error

Cannot convert the "System.Collections.ArrayList+ArrayListEnumeratorSimple" value of type
"System.Collections.ArrayList+ArrayListEnumeratorSimple" to type "System.Int32".

Upvotes: 0

Views: 176

Answers (2)

user4003407
user4003407

Reputation: 22122

If you inspect $input like this:

PS> function f { $input.GetType().FullName } f
System.Collections.ArrayList+ArrayListEnumeratorSimple

then you can notice, that $input is not a collection, but an enumerator for one. So, you do not have random access with indexer for bare $input. If you really want to index $input, then you need to copy its content into array or some other collection:

$InputArray = @( $input )

then you can index $InputArray as normal:

[int]$st1 = $InputArray[0]
[int]$st2 = $InputArray[1]
[int]$st3 = $InputArray[2]
[int]$pm = $InputArray[3]
[int]$cm = $InputArray[4]

Upvotes: 1

Mathias R. Jessen
Mathias R. Jessen

Reputation: 174485

You can't index into $input like that.

You can utilize ForEach-Object:

$st1,$st2,$st3,$pm,$cm = $input |ForEach-Object { $_ -as [int] }

or (preferably), use named parameters:

param(
    [int]$st1,
    [int]$st2,
    [int]$st3,
    [int]$pm,
    [int]$cm
)

$MedMarks = $st1 + $st2 + $st3 - ($pm + $cm)
Write-Host "Med Marks  $MedMarks"

Upvotes: 3

Related Questions