Editing WoW:Handling events (section)

=== The vararg expression ===
The vararg expression (...) may contain additional arguments supplied by the event. Arguments contained in ... can be read by simply assigning them to other variables, possibly using the [[API_select|select]] function to skip forward to a specific argument in the list.

Consider the example of handling [[API_COMBAT_LOG_EVENT|COMBAT_LOG_EVENT]]:
 function eventHandler(self, event, ...)
  if event == "COMBAT_LOG_EVENT" then
   local timestamp, combatEvent, sourceGUID, sourceName, sourceFlags, destGUID, destName, destFlags = 
    ...; -- Those arguments appear for all combat event variants.
   local eventPrefix, eventSuffix = combatEvent:match("^(.-)_?([^_]*)$");
   if eventSuffix == "DAMAGE" then
    -- Something dealt damage. The last 9 arguments in ... describe how it was dealt.
    -- To extract those, we can use the select function:
    local amount, overkill, school, resisted, blocked, absorbed, critical, glancing, crushing = 
     select(select("#", ...)-8, ...); -- select("#", ...) returns number of arguments in the vararg expression
    -- Do something with the damage details ... 
    if eventPrefix == "RANGE" or eventPrefix:match("^SPELL") then
     -- The first three arguments after destFlags in ... describe the spell or ability dealing damage.
     -- Extract this data using select as well:
     local spellId, spellName, spellSchool = select(9, ...); -- Everything from 9th argument in ... onward
     -- Do something with the spell details ...
    end
   end
  end
 end