How to serialize PSCustomObject output to string for Select-String?

[bakamake]

function if return a [pscustomobject] list or stream,effect use pipeline function |select-object xx| select-string key ,how to use simple methods for serializate or format [pscustomobject] stdout to string list

PS /home/bakamake> Get-Childtypes System.Collections.Generic  |select Name|sls link

@{Name=System.Collections.Generic.LinkedList`1}
@{Name=System.Collections.Generic.LinkedList`1+Enumerator}
@{Name=System.Collections.Generic.LinkedListNode`1}

PS /home/bakamake>

function

PS /home/bakamake> get-function -function Get-Childtypes  -path ./dev/pwsh_play/Get-ChildNamespace.ps1
function Get-Childtypes {
param(
    [Parameter(Mandatory, ValueFromRemainingArguments, ValueFromPipeline)]
    [string[]]$Names,
    [switch]$all
)
begin{ $swap = [System.Collections.Generic.HashSet[string]]::new([StringComparer]::OrdinalIgnoreCase)}
process {


    foreach ($name in $Names) {
        [system.AppDomain]::CurrentDomain.GetAssemblies().GetExportedTypes() |
        Where-Object {
            if ($All) { $_.fullname -like "$name*" }
            else { $_.fullname -match "^$name\b" -or $_.fullname -match "^$name" }
        } | ForEach-Object {
            $swap.Add($_.fullname) | Out-Null
        }
    }
}
end{$swap | ForEach-Object { [PSCustomObject]@{ Name = $_ } }}
}

[237dmitry]

If you want to get value from output of PSCustomObject then convert it to strings

([pscustomobject] @{ abc = 'a'; bcd = 'b' } | Out-String) -split "\n" | sls 'a(?=\s)'

[bakamake]

I find out-string -stream return a string stream list like get-content stdout, can use like
[pscustomobject] @{ abc = 'a'; bcd = 'b' } | Out-String -stream | sls 'a(?=\s)'

[bakamake]

I find select -ExpandProperty name is useful ,but only can select a Property

[vladlen-codes]

You're right that -ExpandProperty only accepts a single property at a time, that's a known limitation. But there are several ways to work around this depending on what you're trying to achieve.

If you want multiple expanded properties, use calculated properties:

# Select and expand multiple properties into a flat list
$objects | Select-Object @{N='Combined'; E={$_.Name, $_.Version}}

# Or just select multiple properties normally
$objects | Select-Object Name, Version, Status

If you want the values without the property name headers:

# Expand one property at a time and combine
$names = $objects | Select-Object -ExpandProperty Name
$versions = $objects | Select-Object -ExpandProperty Version

# Or use ForEach-Object for more control
$objects | ForEach-Object { $_.Name, $_.Version }

If you want a flat array of values from multiple properties:

$objects | ForEach-Object { 
    $_.PSObject.Properties | 
    Where-Object Name -in 'Name','Version' | 
    Select-Object -ExpandProperty Value 
}

The most Pythonic/clean approach for multiple expansions:

$objects | ForEach-Object { [PSCustomObject]@{
    Name    = $_.Name
    Version = $_.Version
}}

I hope this was helpful.