Windows PowerShell 3.0 Hash Tables

PowerShell 3.0 [Ordered] Hash Table

What’s new with hash tables in PowerShell 3.0 is they can be[Ordered].  With just one command you can sequence values thus: [Ordered]@{"Key1" = "Value 1";"Key2" = "Value 2; etc …"}.

• Hash Table Refresher
• PowerShell 3.0 [Ordered] Command
• Further Research of PowerShell’s Hash Tables
• Sorting Number Values in a Hashtable
• PowerShell Array

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Hash Table Refresher

Arrays are useful, but only if you have a series of single values.  Hash tables extend arrays by allowing you to have data in the format of Key = Value.

Note 1: Observe the semi-colon; between each pair.

Note 2: If need be, you could display just the Keys with $Countries.Keys. 

Note 3: Speech marks are only required if the key, or its value, contains a space.

PowerShell 3.0 [Ordered] Command

The new feature of PowerShell v 3.0 hash tables is that you can sort the key using the [Ordered] command see this example:

This [Ordered] method sorts on the value, e.g.,  Daffodil, Rose, Shamrock and Thistle.

Alternatively, you can use the old .GetEnumerator() method to sort on Name.

Hash Table Results

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Further Research of PowerShell’s Hash Tables

Hashtables are sometimes called dictionaries; whatever the name, and whatever the spelling, you can list the full set of methods and properties by appending | Get-Member.

One benefit of creating a hash table is that you can add data, for example:

$Countries.Add("France", "Cockrell")

Note 4: The .Add method requires (Parenthesis) not {curly} brackets.

Footnote: This research solves the mystery of why PowerShell doesn’t have a .Delete method; the reason is because it consistently uses .Remove for this task.

Sorting Number Values in a Hashtable

Here is an alternative to using the [Ordered] command; we need Sort-Object if the values are number rather than text.

Learning Points:
Observe the importance of .GetEnumerator.
$Tennis | Sort-Object Value, just would not work, you need that .GetEnumerator() method.

• See more on PowerShell hash tables.
• Also learn about the PowerShell hashtable object.

Summary of PowerShell v 3.0 Ordered Hash Table

Another new feature in version 3.0 is [Ordered] hash tables.  Thanks to this one word [ordered] you can achieve a quicker and better solution for sequencing text values than was possible in PowerShell v 2.0.

See more Microsoft PowerShell v 3.0 examples

• PowerShell 3.0  • What’s New in PowerShell 3.0  • PowerShell v 3.0 ISE  • PowerShell Home

• Get-NetAdapter  • Disable-NetAdapter  • Enable-NetAdapter  • Get-NetIPConfiguration

• PowerShell Network Cmdlets  • PowerShell 3.0 Logon Script  • PowerShell Show-Command