Variables seem the same but don't match - arrays

Question

I am trying to compare 2 values in variables to see if they're the same, in the PowerShell output I can see that some combinations should be true!
First, without the making of $vergelijking1 and $vergelijking2 it showed as if $nummersPOs[$counter] and $object.'col1' were the same but the if statement was never true.
The only thing I could think of as to why it would fail is that 1 of the variables comes from an array. When I changed both types to String I could indeed see that there was some hidden text but I don't understand why my if statment is never true now. It writes "test2" but should write "inside the loop".
[System.Collections.ArrayList]$data = Import-Csv "C:\Users\UserName\Documents\test.csv"
[System.Collections.ArrayList]$NummersPOs = Import-Csv "C:\Users\UserName\Documents\test.csv" | select "col1" -Unique
$counter = 0
foreach ($object in $NummersPOs) {
$newCSV = New-Object System.Collections.ArrayList
foreach ($object in $data) {
if ($object."col2") {
$index = $newCSV.Add($object)
[string]$vergelijking1 = $NummersPOs[$counter]
#$vergelijking1 = $vergelijking1 -replace '\D+(\d+)','$1'
$vergelijking1
[string]$vergelijking2 = $object.'col1'
$vergelijking2
if ($vergelijking1 -contains $vergelijking2) {
Write-Host "inside the loop"
} else {
Write-Host "test2"
}
}
}
$counter++
}
$newCSV | Export-Csv "C:\Users\UserName\Documents\test2.csv"
Sample output:
#{col1=632424}
632424
test2
#{col1=632424}
632446
test2
As you can see, the first one should have been true already. -contain or -like both give false BTW.

Answer 1

Take an actual look at your operands:
"#{col1=632424}" ← $vergelijking1
"632424" ← $vergelijking2
These two strings are obviously not equal, so why would you expect them to be?
You're assigning an object to $verglijking1 and cast it to a string, so you actually get a string representation of that object (#{col1=632424}). To $verglijking2 you assign the value of an object property ($object.'col1'). Even though you still cast the value to a string you only get the string representation of the value, not of the object.
Also, you can't use the -contains operator, as #Mathias R. Jesson pointed out, since that operator is for checking the presence of elements in an array. The -like operator would've worked, but you'd have to put wildcards before and after the value ("*$verglijking2*"). Without wildcards the operator behaves exactly like the -eq operator.
With that said, all the casting you do in your script is completely unnecessary. Handle both variables the same way and use the correct comparison operator, and the problem will disappear.
if ($object.col2) {
$vergelijking1 = $NummersPOs[$counter].col1
$vergelijking2 = $object.col1
if ($vergelijking1 -eq $vergelijking2) {
Write-Host "inside the loop"
} else {
Write-Host "test2"
}
}