Determine if an AddOn has been loaded.

loaded = IsAddOnLoaded(index or "name")

Parameters

Arguments

(index or "name")

index 

Integer - The index of the AddOn in the user's AddOn list. You cannot access Blizzard-provided AddOns through this mechanism.

name 

String - The name of the AddOn to be queried. You can access Blizzard-provided AddOns through this mechanism.

Returns

loaded 

Flag - Indicates if the AddOn has been loaded, 1 if it has been, nil if it has not.

Example

if (IsAddOnLoaded("AddonName")) then
  do stuff
end