Powershell where-object complex logic

Question

I am having trouble coming up with a way to do complex logic using the where-object in PowerShell

I have the following code, but separating the and from the ORs is not working as intended.

Get-ADComputer -Filter * | Where-Object {
    ($_.Enabled) -and
    (($_.DistinguishedName -contains 'world') -or
    ($_.DistinguishedName -contains 'foo')) -and
    (($_.SID -contains 'bar') -or
    ($_.SID -contains 'something else'))
}

If I do this in c# I get results, but in powershell I do not.

Any thoughts on how to get around this?

TIA

what happens if you add one test at a time? at what point does the test fail to give the expected results? — Lee_Dailey
– Lee_Dailey, Commented Mar 19, 2021 at 15:51
also, the -contains operator is a collection operator, not a string operator. you likely otta use either -match or -like with wildcards. — Lee_Dailey
– Lee_Dailey, Commented Mar 19, 2021 at 15:55
Unusually, -and and -or have equal precedence in powershell. Usually "and" has higher precedence. — js2010
– js2010, Commented Nov 6 at 14:39

Santiago Squarzon · Accepted Answer · 2025-11-06 15:05:53Z

4

The main issue is very likely with -contains, this is the operator you would use to check whether an item exists in an array, for example:

'apple', 'banana', 'pineapple' -contains 'apple'

# True

This operator does not work in partial matches, only exact ones. For partial matches you could use -like or, the recommended one in this case would be the -match operator with a regex OR pattern:

Get-ADComputer -Filter 'enabled -eq $true' | Where-Object {
    $_.DistinguishedName -match 'world|foo' -and
    $_.SID -match 'bar|something else'
}

Using -like the condition becomes very similar as what you currently have, however you do need the * wildcards (for the partial match), no parentheses are needed:

Get-ADComputer -Filter 'enabled -eq $true' | Where-Object {
    $_.DistinguishedName -like '*world*' -or $_.DistinguishedName -like '*foo*' -and
    $_.SID -like '*bar*' -or $_.SID -like '*something else*'
}

If Where-Object isn't performing well (it can be slow), you might consider a more classic approach using foreach and if conditions:

$result = foreach ($computer in Get-ADComputer -Filter 'enabled -eq $true') {
    if ($computer.DistinguishedName -match 'World|Foo' -and $computer.SID -match 'bar|something else') {
        $computer
    }
}

edited Nov 6 at 15:05

answered Mar 19, 2021 at 16:06

Santiago Squarzon

65.5k5 gold badges26 silver badges59 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

john Over a year ago

Thank you, this is exactly the knowledge sharing I needed. I appreciate every ones input and sorry for my lack of knowledge.

Lee_Dailey · Accepted Answer · 2021-03-19 16:33:45Z

2

~~this is not an Answer - so please let me know when you have read it so that i can delete it.~~

this is your code with more informative indentation, with the needless extra parens removed, and with spaces around the operators.

Get-ADComputer -Filter * |
    Where-Object {
        $_.Enabled -and
        ($_.DistinguishedName -Contains "world" -or
            $_.DistinguishedName -Contains "foo") -and
        ($_.SID -Contains "bar" -or
            $_.SID -Contains "something else")
        }

note that the -contains operator is NOT for strings ... it is for membership in a collection. if you want to test against strings, use -match, or .Contains(), or -like with wildcards.

edited Mar 19, 2021 at 16:33

answered Mar 19, 2021 at 15:59

Lee_Dailey

7,5292 gold badges25 silver badges27 bronze badges

6 Comments

Mathias R. Jessen Over a year ago

"the -contains operator is NOT for strings" - kinda sounds like an answer Lee ;-)

Lee_Dailey Over a year ago

@MathiasR.Jessen - ok ... i will remove that part of the Answer. thank you for the feedback! [grin]

Mathias R. Jessen Over a year ago

Why not just remove the disclaimer? Why do you hate answering questions so much? :)

Lee_Dailey Over a year ago

@MathiasR.Jessen - many times the Answer feels more like a comment to me. i seem to have a bit of a problem deciding what side of the line this one otta be on.

john Over a year ago

Read, Thank you very much.

|

js2010 · Accepted Answer · 2025-11-06 15:43:46Z

Powershell doesn't give "and" a higher precedence than "or", like in every other language. So instead of putting parentheses everywhere and hoping for the best, just put them around the "and" parts so they evaluate first. Note that -contains only matches whole words in an array. .contains() would work, but it's case sensitive. -match is probably the best alternative. The first "and" evaluates first anyway (left to right), but it's nice to have some symmetry. (I can't make it say powershell instead of bash?)

$objects = 'enabled,distinguishedname,sid
true,world,1
"",world2,1
true,foo,bar
true,foo,something else' | convertfrom-csv 

$objects | Where-Object {
    ($_.Enabled -and $_.DistinguishedName -contains 'world') -or
    ($_.DistinguishedName -contains 'foo' -and $_.SID -contains 'bar') -or
    $_.SID -contains 'something else'
}

Output

enabled distinguishedname sid
------- ----------------- ---
true    world             1
true    foo               bar
true    foo               something else

Collectives™ on Stack Overflow

Powershell where-object complex logic

3 Answers 3

1 Comment

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related