Action Slot IDs can vary for some classes and are completely arbitrary to the buttons they exist in. As of 1.11, World of Warcraft allows 120 Action Slot IDs, numbered from 1-120. The IDs 1-72 are used by the six default bars (see below for the button ranges). IDs 73-108 are used by the stance bars of some classes. IDs 109-120 have no default uses.
Default UI use of Action slot IDs
ActionBar page 1: slots 1 to 12 -- Note exceptions below for other classes
ActionBar page 2: slots 13 to 24
ActionBar page 3 (Right ActionBar): slots 25 to 36
ActionBar page 4 (Right ActionBar 2): slots 37 to 48
ActionBar page 5 (Bottom Right ActionBar): slots 49 to 60
ActionBar page 6 (Bottom Left ActionBar): slots 61 to 72
Warriors
ActionBar page 1 Battle Stance: slots 73 to 84
ActionBar page 1 Defensive Stance: slots 85 to 96
ActionBar page 1 Berserker Stance: slots 97 to 108
Druids
???
Rogues
ActionBar page 1 Stealth: slots 73 to 84
Example Code
This function will display the contents of each of the 120 action slots (skipping empty ones) in the default chat frame. To use, type "/script reportActionButtions()".
function reportActionButtons() local lActionSlot = 0; for lActionSlot = 1, 120 do local lActionText = GetActionText(lActionSlot); local lActionTexture = GetActionTexture(lActionSlot); if lActionTexture then local lMessage = "Slot " .. lActionSlot .. ": [" .. lActionTexture .. "]"; if lActionText then lMessage = lMessage .. " \"" .. lActionText .. "\""; end DEFAULT_CHAT_FRAME:AddMessage(lMessage); end end end