Associative Arrays

In computer science, an associative array, map, symbol table, or dictionary is an abstract data type composed of a collection of (key, value) pairs, such that each possible key appears at most once in the collection. An associative array differs from a “normal” array in one major way: rather than being indexed numerically (i.e. 0, 1, 2, 3, …), it is indexed by a key, or a language-like word. A Scripting.Dictionary is a standard object provided by the Microsoft ScripTing Runtime (scrrun.dll) dependency and is commonly used in VBScript, a reference to which needs to be added in order to create an object in your AutoIt project.
A dictionary object example by MHz

Global $vKey, $sItem, $sMsg, $oDictionary 

; Create dictionary object
$oDictionary = ObjCreate("Scripting.Dictionary")

If @error Then
    MsgBox(0, '', 'Error creating the dictionary object')
Else
    ; Add keys with items
    $oDictionary.Add ("One",    "Same"  )
    $oDictionary.Add ("Two",    "Car"   )
    $oDictionary.Add ("Three",  "House" )
    $oDictionary.Add ("Four",   "Boat"  )

    If $oDictionary.Exists('One') Then
        ; Display item
        MsgBox(0x0, 'Item One', $oDictionary.Item('One'), 2)
        ; Set an item
        $oDictionary.Item('One') = 'Changed'
        ; Display item
        MsgBox(0x20, 'Did Item One Change?', $oDictionary.Item('One'), 3)
        ; Remove key
        $oDictionary.Remove('One')
        ; 
        $oDictionary.Key ('Two') = 'Bike'
    EndIf

    Sleep(1000)

    ; Store items into a variable
    For $vKey In $oDictionary
       $sItem &= $oDictionary.Item($vKey) & @CRLF
    Next

    ; Display items
    MsgBox(0x0, 'Items Count: ' & $oDictionary.Count, $sItem, 3)

    ; Add items into an array
    $aItems = $oDictionary.Items

    ; Display items in the array
    For $i = 0 To $oDictionary.Count -1
        MsgBox(0x0, 'Items [ ' & $i & ' ]', $aItems[$i], 2)
    Next

    Sleep(1000)

    ; Add keys into an array
    $aKeys = $oDictionary.Keys

    ; Display keys in the array
    For $i = 0 To $oDictionary.Count -1
        MsgBox(0x0, 'Keys [ ' & $i & ' ]', $aKeys[$i], 2)
    Next
EndIf