如何在Powershell中比较关联数组？

Question

我有两个关联数组，

$a = @{"k1"="v1"; "k2"=@{"k21"="v21"}} 

$b = @{"k1"="v1"; "k2"=@{"k21"="v21"}} 

我想知道有没有什么好的方法可以在不编写自己的函数的情况下进行比较？

Answer 1

除了编写一个函数来比较每个键的值（如果该值不是原始对象，则可能是递归的）之外，我不知道有什么方法。但是，PowerShell 中的关联数组只是 .NET 类型 (System.Collections.Hashtable)。您可能希望通过将 .NET 标记添加到您的问题中，向更广泛的 .NET 受众开放这个问题。

Answer 2

为了完整起见，这里有一个用于比较哈希表的简单函数：

function Compare-Hashtable(
  [Hashtable]$ReferenceObject,
  [Hashtable]$DifferenceObject,
  [switch]$IncludeEqual
) {
  # Creates a result object.
  function result( [string]$side ) {
    New-Object PSObject -Property @{
      'InputPath'= "$path$key";
      'SideIndicator' = $side;
      'ReferenceValue' = $refValue;
      'DifferenceValue' = $difValue;
    }
  }

  # Recursively compares two hashtables.
  function core( [string]$path, [Hashtable]$ref, [Hashtable]$dif ) {
    # Hold on to keys from the other object that are not in the reference.
    $nonrefKeys = New-Object 'System.Collections.Generic.HashSet[string]'
    $dif.Keys | foreach { [void]$nonrefKeys.Add( $_ ) }

    # Test each key in the reference with that in the other object.
    foreach( $key in $ref.Keys ) {
      [void]$nonrefKeys.Remove( $key )
      $refValue = $ref.$key
      $difValue = $dif.$key

      if( -not $dif.ContainsKey( $key ) ) {
        result '<='
      }
      elseif( $refValue -is [hashtable] -and $difValue -is [hashtable] ) {
        core "$path$key." $refValue $difValue
      }
      elseif( $refValue -ne $difValue ) {
        result '<>'
      }
      elseif( $IncludeEqual ) {
        result '=='
      }
    }

    # Show all keys in the other object not in the reference.
    $refValue = $null
    foreach( $key in $nonrefKeys ) {
      $difValue = $dif.$key
      result '=>'
    }
  }

  core '' $ReferenceObject $DifferenceObject
}

一些示例输出：

> $a = @{ 'same'='x'; 'shared'=@{ 'same'='x'; 'different'='unlike'; 'new'='A' } }
> $b = @{ 'same'='x'; 'shared'=@{ 'same'='x'; 'different'='contrary' }; 'new'='B' }
> Compare-Hashtable $a $b

InputPath          ReferenceValue   DifferenceValue   SideIndicator
---------         --------------   ---------------   -------------
shared.different   unlike           contrary          <>
shared.new         A                                 <=
new                                 B                =>