for i in print, "123" , "368" do
end
输入：123 368
function iter (a, i)
i = i + 1
local v = a[i]
if v then
return i, v
end
end
a = {"one", "two", "three"}
for i, v in iter, a, 0 do
print(i, v)
end
输出：1 one
2 two
3 three
注：in会执行放入的函数并将后续变量作为参数传入函数中有趣的事
原文：http://www.cnblogs.com/ad-1990/p/4124965.html
