Powershell - remove duplicates from 2 arrays using wildcards - arrays

Question

I am trying to remove duplicates and leave only unique entries from the output of 2 queries.
I am pulling a list of installed Windows Updates using the following (also stripping 12 chars of whitespace and dropping to lower case:
$A = #(Get-HotFix | select-object #{Expression={$_.HotFixID.ToLower()}} | ft -hidetableheaders | Out-String) -replace '\s{12}',''
I am then querying a list of available files in a folder and stripping 3 trailing whitespace chars using:
$B = #(Get-ChildItem D:\y | select-object 'Name' | ft -hidetableheaders | Out-String) -replace '\s{3}',''
The problem I have is that the first query ($A) returns output like:
kb4040981
kb4041693
kb2345678
kb8765432
While the second query ($B) returns output like:
windows8.1-kb4040981-x64_d1eb05bc8c55c7632779086079c7759f40d7386f.cab
windows8.1-kb4041687-x64_3bdf264bcfc0dda01c2eaf2135e322d2d6ce6c64.cab
windows8.1-kb4041693-x64_359b7ac71a48e5af003d67e3e4b80120a2f5b570.cab
windows8.1-kb4049179-x64_e6ec21d5d16fa6d8ff890c0c6042c2ba38a1f7c4.cab
I need to compare the 2 outputs using wildcards around each entry in the $A array (I think), and where it exists in $B remove the entire line from $B array.
I cannot truncate the output of $B as I need to use the full filenames in a subsequent process.
IE in the example output above, the entire FIRST and THIRD lines would be remove from the $B array and other lines left intact.
I have tried numerous methods from online searches, and used foreach loops, all to no avail.
Thank you in advance for any assistance.

Answer 1

What did you try with foreach loops that didn't work? Unless your output is huge, this method is pretty striaght forward.
$a = "kb4040981","kb4041693","kb2345678","kb8765432","test"
[System.Collections.ArrayList]$b = "windows8.1-kb4040981-x64_d1eb05bc8c55c7632779086079c7759f40d7386f.cab","windows8.1-kb4041687-x64_3bdf264bcfc0dda01c2eaf2135e322d2d6ce6c64.cab","windows8.1-kb4041693-x64_359b7ac71a48e5af003d67e3e4b80120a2f5b570.cab","windows8.1-kb4049179-x64_e6ec21d5d16fa6d8ff890c0c6042c2ba38a1f7c4.cab"
$toRemove = New-Object System.Collections.ArrayList
foreach($kb in $a)
{
foreach($line in $b)
{
if($line -match $kb)
{
write-host "$kb found in: $line" -ForegroundColor Green
$toRemove.add($line) | out-null
}
}
}
foreach($line in $toRemove)
{
$b.Remove($line)
}
$b
Hope it helps.

Answer 2

I would recommend for you to take a little time to learn the very basics of Powershell. When you use format cmdlets and text files instead of objects you cut yourself of the good stuff. ;-)
Here is how I would start the task:
$A = Get-HotFix
$B = Get-ChildItem D:\y | Select-Object -Property Name,#{Name='HotFixID';Expression={($_.BaseName -split '-')[1]}}
Compare-Object -ReferenceObject $A -DifferenceObject $B -Property 'HotFixID' -PassThru

Answer 3

Sincere thanks to sambardo for his patience and input! The final working solution based on his excellent recommendation is:
$a = (Get-Hotfix).hotfixID
$b = (Get-ChildItem D:\y\ -file *.cab).name
$toRemove = New-Object System.Collections.ArrayList
foreach($kb in $a)
{
foreach($line in $b)
{
if($line -match $kb)
{
# write-host "$kb found in: $line" -ForegroundColor Green
$toRemove.add($line) | out-null
}
}
}
foreach($line in $toRemove)
{
$b.Remove($line)
}
$b