Powershell find value in arraylist - powershell

Question

I hope you can help me out. I work with two ArrayLists:
array1 is filled with log.csv (contains header and logon-data, values of column 'pc' are unique). It's defined as ArrayList because I want to add entries.
#pc,name,date,city
#pc-x,name-1,2017-01-01,berlin
#pc-y,name-1,2017-01-02,berlin
#pc-z,name-2,2017-01-02,munich
[System.Collections.ArrayList]$array1 = Import-Csv log.csv
array2 is filled during runtime
$array2=[System.Collections.ArrayList]#()
... ForEach-Object {
$array2.Add([PSCustomObject]#{ pc=$pcname
name=$loginname
date=$logindate }) >$null }
What I want to do:
Update array1.date=array2.date where array1.pc=array2.pc
If no entry found in array1 I want to add it:
$array1.Add([PSCustomObject]#{ pc=$pcname
name=$loginname
date=$logindate
city='[unknown]' }) >$null
Finally array1 is exported again:
$array1 | Export-Csv log.csv -Encoding UTF8 -NoTypeInformation
So the question is: how can I find the entry in array1 and update it? Trying hard for days now ...

Answer 1

try Something like this:
$array1=import-csv "C:\temp\log.csv"
$array2=import-csv "C:\temp\log2.csv"
#modify founded and output not founded
$toadd=$array2 | %{
$current=$_
$founded=$array1 | where pc -eq $current.pc | %{$_.date=$current.date;$_}
if ($founded -eq $null)
{
$current.city='UNKNOW'
$current
}
}
#output of $array1 modified and elements to add
$array1, $toadd

Answer 2

Here is a sample I created that might help. Note: I use List types instead of ArrayList ones. Also, it assumes only one possible matching PC name in the data to be updated. You'll have to alter it to update the file since it merely updates the first List variable. Let me know how it goes.
[PSCustomObject]
{
[string] $pc,
[string] $name,
[string] $date,
[string] $city
}
[System.Collections.Generic.List[PSCustomObject]] $list1 = Import-Csv "C:\SOSamples\log.csv";
[System.Collections.Generic.List[PSCustomObject]] $list2 = Import-Csv "C:\SOSamples\log2.csv";
[PSCustomObject] $record = $null;
[PSCustomObject] $match = $null;
foreach($record in $list2)
{
# NOTE: This only retrieves the FIRST MATCHING item using a CASE-INSENSITIVE comparison
$match = $list1 | Where { $_.pc.ToLower() -eq $record.pc.ToLower() } | Select -First 1;
if($match -eq $null)
{
Write-Host "Not Found!";
$list1.Add($record);
}
else
{
Write-Host "Found!";
$match.date = $record.date;
}
}
Write-Host "--------------------------------------------------------------------"
foreach($record in $list1)
{
Write-Host $record
}