Module:NUMBEROFSECTIONS/sandbox explained

local p =

-- Counting function accepting a string haystack and table of needleslocal function count(haystack, needles) local number = 0 -- While we have needles to look for for index, needle in ipairs(needles) do -- find them all in our haystack for m in string.gmatch(haystack, needle) do number = number + 1 end end return numberend

-- Function takes any number of # delimited page names and section level numbersfunction p.sections(frame) local total = 0 local needles = local haystack = -- Separate page names from # delimited string into table local pages = mw.text.split(frame.args[1], '%s?#%s?') -- Separate whitespace delimited section level numbers into table local levels = mw.text.split(frame.args['level'], '%s*') -- Iterate through levels for level in mw.text.gsplit(table.concat(levels), ) do -- and add the level needle to needles needles[#needles + 1] = '\n'..string.rep('=', tonumber(level))..'[^=]' end -- For each page name in pages for index, page in ipairs(pages) do -- create a haystack to search from the page content haystack = mw.title.new(page):getContent -- If we've requested the content of a legitimate page if haystack then --pass the raw markup and needles to count and add the return to total total = total + count(haystack, needles) end end --then return how many sections of the required level are in all the pages passed return totalend

return p