How to get CSV column based on variable

Question

I am trying to create a script that should read CSV column-based array variables to execute some analysis on them. I have created a script that runs fine if I use the manual array column reading which is way too hard for a huge file. Is there a way to make it work when I use variables from an array?

Below is a part of the script which I am having trouble with:

$myarray= "col1", "col2", "col3"
$mycsv=import-csv e:\text.csv
$mycsv.$myarray[0] # this does not work
$mycsv.col1        # this works fine

Answer 1

PowerShell allows you to use expressions as property names.

In your case, because the expression involves an array subscript, you need to enclose it in () , the grouping operator :

$mycsv.($myarray[0])

---

A simplified example:

$myarray= "col1", "col2", "col3"

$obj = [pscustomobject] @{ col1 = 'foo' }

$obj.($myarray[0]) # -> 'foo'

Answer 2

Other solution:

$myarray= "col1", "col2", "col3"

$obj = [pscustomobject] @{ col1 = 'foo' }

$obj.psobject.Properties[$myarray[0]].Value

If you want a complet example for csv:

#columns to select
$myarray= "col1", "col2", "col3"

#import csv
$Rows = import-csv "e:\text.csv"   #csv have colum Nom, Prenom, age, autre

#take columns list into $myarray and used into csv
$PropertyToTake=$Rows | Get-Member -MemberType NoteProperty | where Name -in $myarray

#loop on all rows csv and extract only columns values of myarray
$Rows | %{

        $CurrentRow=$_

        #create empty object
        $Object=[pscustomobject]@{}

        #Add properties to object with property name and value of csv
        $PropertyToTake | %{Add-Member -InputObject $Object -MemberType NoteProperty -Name $_.Name -Value $CurrentRow.psobject.Properties[$_.Name].Value }

        #send object on output
        $Object
}