Problem
You have a collection of items that you want to access through a label that you provide.
Solution
To define a mapping between labels and items, use a hashtable (associative array):
PS >$myHashtable = @{} PS > PS >$myHashtable = @{ Key1 = "Value1"; "Key 2" = 1,2,3 } PS >$myHashtable["New Item"] = 5
PS >
PS >$myHashTable
Name
Value
Key 2
{1, 2, 3}
New Item
5
Key1
Value1
Discussion
Hashtables are much like arrays that allow you to access items by whatever label you want—not just through their index in the array. Because of that freedom, they form the keystone of a huge number of scripting techniques. Since they allow you to map names to values, they form the natural basis for lookup tables such as ZIP codes and area codes. Since they allow you to map names to fully featured objects and script blocks, they can often take the place of custom objects. Since you can map rich objects to other rich objects, they can even form the basis of more advanced data structures such as caches and object graphs.
This label and value mapping also proves helpful in interacting with cmdlets that support advanced configuration parameters, such as the calculated property parameters available on the FormatTable and SelectObject cmdlets.
