`Select-Object` `-InputObject` not work compared to pipeline input

[PtJade-Ceramic]

Prerequisites

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• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

I am experiencing a problem with Select-Object 's parameter -InputObject.

I think its output should be the same as that responding to the value from the pipeline.

However it echos an empty set only.

Expected behavior

PS> Get-Member -InputObject (Get-Help Get-Help) | Select-Object MemberType -Unique

  MemberType
  ----------
      Method
NoteProperty

Actual behavior

PS> Select-Object -InputObject (Get-Help Get-Help | Get-Member) MemberType -Unique

MemberType
----------

Error details

Environment data

PS> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      7.6.0-rc.1
PSEdition                      Core
GitCommitId                    7.6.0-rc.1
OS                             Microsoft Windows 10.0.26200
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.4
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

PS> $PSVersionTable.PSVersion

Major  Minor  Patch  PreReleaseLabel BuildLabel
-----  -----  -----  --------------- ----------
7      6      0      rc.1

Visuals

No response

[mklement0]

Select-Object's -InputObject parameter isn't designed to accept multiple input objects by argument - it is an implementation detail that facilitates pipeline input, where multiple objects are passed one by one.

For background information, see:

• Consistently document a scalar -InputObject parameter as an implementation detail or make item-by-item processing cmdlets explicitly iterate over collections #4242