Creating nested data structure

[bgrossman]

Hi all

I have a string like ‘A/B/C’ that I’m trying to get into a nested structure like the following:

PowerShell

$folders = @( @{ Name = 'A' Folders = @( @{ Name = 'B' Folders = @( @{ Name = 'C' Folders = @() } ) } ) } )

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$folders = @(     @{         Name    = 'A'         Folders = @(             @{                 Name    = 'B'                 Folders = @(                     @{                         Name = 'C'                         Folders = @()                     }                 )             }         )     } )

I thought this would be pretty straightforward using recursion, but only the top-level hashtable (“A”) gets added to $bar…

PowerShell

function Foo { param ( [Parameter()] [string[]] $Path, [Parameter()] [hashtable[]] [ref]$Folders ) if (!$Path) { return } $current, $children = $Path $Folders.Value += @{ Name = $current Folders = @() } Foo $children ([ref]$Folders.Value[-1].Folders) } $bar = @() Foo 'A/B/C'.Split('/') ([ref]$bar)

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function Foo {     param (         [Parameter()]         [string[]]         $Path,           [Parameter()]         [hashtable[]]         [ref]$Folders     )       if (!$Path) {         return     }       $current, $children = $Path       $Folders.Value += @{         Name    = $current         Folders = @()     }       Foo $children ([ref]$Folders.Value[-1].Folders) }   $bar = @() Foo 'A/B/C'.Split('/') ([ref]$bar)

Any ideas? Must be some issue with passing by ref the deeper array?

Note I have an array of strings like ‘A/B/C’ (e.g. ‘A/B/D’, ‘D/E/F) to add to the structure, but that should be easy once I get past this first issue…

• This topic was modified 1 week, 6 days ago by bgrossman.
• This topic was modified 1 week, 6 days ago by grokkit.
• This topic was modified 1 week, 6 days ago by grokkit. Reason: gist display

[Rob Simmers Participant Topics: 17 Replies: 1951 Points: 3,986Rank: Community Hero]

Here is one way, build it backwards:

PowerShell

$arr = 'A','B','C','D','E','F','G' [array]::Reverse($arr) $lastObj = $null foreach ($item in $arr) { $lastObj = [pscustomobject]@{ Name = $item Folders = @($lastObj) } } $lastObj | ConvertTo-Json -Depth 30

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$arr = 'A','B','C','D','E','F','G' [array]::Reverse($arr)   $lastObj = $null foreach ($item in $arr) {     $lastObj = [pscustomobject]@{         Name    = $item         Folders = @($lastObj)     } }   $lastObj | ConvertTo-Json -Depth 30

[Mike R. Participant Topics: 5 Replies: 249 Points: 985Rank: Major Contributor]

Wow this was a fun exercise.  Haven’t messed with recursion much since my freshman year at college.  I created a recursive function that will create the data structure you want.

PowerShell

function folders([System.Collections.ArrayList]$Name, $ht = @{}) { $ht.name = $Name[0] if ($Name.count -eq 1) {$ht.folders = @(); $ht} #base case else { $Name.RemoveAt(0) $ht.folders = @(folders -ht $ht.Clone() -Name $Name) $ht #recurse case } #else } #function $TestData = @("A/B/C","D/E/F") $Result = $TestData | ForEach-Object {folders -Name @($_ -split "/")}

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function folders([System.Collections.ArrayList]$Name, $ht = @{}) {     $ht.name = $Name[0]     if ($Name.count -eq 1) {$ht.folders = @(); $ht} #base case     else {         $Name.RemoveAt(0)         $ht.folders = @(folders -ht $ht.Clone() -Name $Name)         $ht #recurse case     } #else } #function   $TestData = @("A/B/C","D/E/F") $Result = $TestData | ForEach-Object {folders -Name @($_ -split "/")}

 

[AdminOfThings45 Participant Topics: 1 Replies: 95 Points: 435Rank: Contributor]

I like using a Stack object for this exercise:

PowerShell

$folders = 'a/b/c','d/e/f' | Foreach-Object { [system.collections.stack]$stack = $_ -split '/' | Foreach-Object { [ordered]@{name = $_; folders = @()} } while ($stack.Count -gt 1) { $stack.ToArray()[1].Folders = ,$stack.Pop() } $stack } Remove-Variable stack

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$folders = 'a/b/c','d/e/f' | Foreach-Object {     [system.collections.stack]$stack = $_ -split '/' | Foreach-Object {         [ordered]@{name = $_; folders = @()}     }     while ($stack.Count -gt 1) {         $stack.ToArray()[1].Folders = ,$stack.Pop()     }     $stack } Remove-Variable stack

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