How to match any part of a property string using Where-Object - string

Question

I have an array $array with many elements, an example looks like this:
ProfileID : 100
UID : 17
Name : SharePoint
Description : SharePoint Server Description
Now I am trying to filter by Name property, string to match is:
$string
SharePoint Policy Assignment
I have tried:
$array | Where-Object {$_.Name -like "$string"}
no match
$array | Where-Object {$_.Name -like "$string*"}
no match
$array | Where-Object {$_.Name -match "$string"}
no match
Is this possible using PowerShell? What am I missing?

Answer 1

The -like operator in PowerShell is used for a wildcard match, so you need to use the wildcard character, the asterisk, *.
Imagine this scenario, where I'm trying to match a particular Windows Service.
$svcs = Get-Service | Select-Object -first 15
C:\temp\blog> $svcs
Status Name DisplayName
------ ---- -----------
Stopped AJRouter AllJoyn Router Service
Stopped ALG Application Layer Gateway Service
Running AMD External Ev... AMD External Events Utility
Stopped AppIDSvc Application Identity
Running Appinfo Application Information
Stopped AppMgmt Application Management
Stopped AppReadiness App Readiness
Stopped AppVClient Microsoft App-V Client
Stopped AppXSvc AppX Deployment Service (AppXSVC)
Stopped aspnet_state ASP.NET State Service
Stopped AssignedAccessM... AssignedAccessManager Service
Running AsSysCtrlService ASUS System Control Service
Running AudioEndpointBu... Windows Audio Endpoint Builder
Running Audiosrv Windows Audio
Running AUEPLauncher AMD User Experience Program Launcher
To use the -Like operator to get a match, I have to provide a Wildcard Character, like this.
$svcs | Where-Object Name -like App*
Status Name DisplayName
------ ---- -----------
Stopped AppIDSvc Application Identity
Running Appinfo Application Information
Stopped AppMgmt Application Management
Stopped AppReadiness App Readiness
Stopped AppVClient Microsoft App-V Client
Stopped AppXSvc AppX Deployment Service (AppXSVC)
Try your operation using a WildCard, and I bet it will work :)
One other thing I noted, your $string is equal to SharePoint Policy Assignment, but the column you're comparing on of .Name is just SharePoint.

Answer 2

To complement FoxDeploy's helpful answer:
With collections that are already are in memory or easily fit, you can use member-access enumeration for a more convenient syntax that also results in much faster execution:
#($array.Name) -like $string # returns sub-array of matching elements
-like, when given an array as the LHS, acts as a filter: only those array elements that match the wildcard expression on the RHS are returned (also as an array).
Note the need for #(...) to ensure that $array.Name is an array, because a single-element array would result in the .Name property getting returned as a scalar (a single string), in which case -like would return a Boolean ($true or $false) rather than acting as a filter.
Also note that many PowerShell cmdlets directly support wildcard expressions as parameter values:
Taking Get-Service as an example, its (implied) -Name parameter supports wildcards:
Get-Service *router* # returns all services whose Name contains "router"
To determine a given cmdlet parameter's wildcard support:
PS> Get-Help Get-Service -Parameter Name
-Name <String[]>
Specifies the service names of services to be retrieved. Wildcards are permitted. By default, this cmdlet gets all of the services on the computer.
Required? false
Position? 1
Default value None
Accept pipeline input? True (ByPropertyName, ByValue)
Accept wildcard characters? false
It should be the Accept wildcard characters? value being true that indicates support for wildcard expressions, however, this is unfortunately not reliable, so also check the parameter description; here, the descriptin part Wildcards are permitted provides the information.
GitHub issue #4716 describes the problem and asks to make the programmatic discoverability of wildcard support reliable.