In Lua, this would be: function init(a,b,c) local x = a or 0 local y = b or 0 local z = c or 0 end "and" and "or" short circuit eval

In Lua, this would be: function init(a,b,c) local x = a or 0 local y = b or 0 local z = c or 0 end "and" and "or" short circuit evaluation in Lua; nil and false are false, everything else (including 0) is considered true.