mao
6/30/2017 - 4:11 PM

Powershell function which merges Hashtables similarly to how lodash _.merge does. Answers question "How do I merge several hashtables whil

Powershell function which merges Hashtables similarly to how lodash _.merge does. Answers question "How do I merge several hashtables while being able both add new keys and overwrite old ones?"

Merge-Hashtables.ps1
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<#  .SYNOPSIS
      Merges any number of hashtables into one

    .DESCRIPTION
      Merges any number of hashtables taken both from pipeline and arguments, with the hashtables in the right overwriting the keys with the same names from hastables in the left

    .EXAMPLE
      $a = @{a = 'a1'; b = 'a2'}
      $b = @{b = 'b1'; c = 'b2'}
      $c = @{c = 'c1'; d = 'c2'}

      PS> Merge-Hashtables $a $b

      Name                  Value                                                                                                                                                              
      ----                  -----
      a                     a1
      b                     b1
      c                     b2

    .EXAMPLE
      PS> $a, $b | Merge-Hashtables $c

      Name                  Value                                                                                                                                                              
      ----                  -----
      a                     a1
      b                     b1
      c                     c1
      d                     c2  
#>

Function Merge-Hashtables {
    $Result = @{}
    ($Input + $Args) | 
        Where   { ($_.Keys -ne $null) -and ($_.Values -ne $null) -and ($_.GetEnumerator -ne $null) } | 
        ForEach { $_.GetEnumerator() } | 
        ForEach { $Result[$_.Key] = $_.Value } 
    $Result
}