Hashtables

A hashtable is an associative array or an indexed array. Individual elements in the array are created with a unique key. Keys cannot be duplicated within the hashtable.

Hashtables are important in PowerShell. They are used to create custom objects, to pass parameters into commands, to create custom properties using Select-Object, and as the type for values assigned to parameter values of many different commands, and so on.

Note

For finding commands that use Hashtable as a parameter, we use the following:Get-Command -ParameterType Hashtable

This topic explores creating hashtables, selecting elements, enumerating all values in a hashtable, as well as adding and removing elements.

Creating a hashtable

An empty hashtable is created the same as the following:

$hashtable = @{}

A hashtable with a few objects looks the same as the following:

$hashtable = @{Key1 = "Value1"; Key2 = "Value2"}

Elements in a hashtable may be spread across multiple lines:

$hashtable = @{ 
    Key1 = "Value1" 
    Key2...