【入门夯实】闭包里的i：循环变量捕获的真相

local callbacks = {}
local i = 1
while i <= 3 do
    callbacks[#callbacks + 1] = function()
        return i
    end
    i = i + 1
end
sendmsg(nil, 1, "三个回调都返回 " .. callbacks[1]())

local callbacks = {}
for i = 1, 3 do
    callbacks[#callbacks + 1] = function()
        return i
    end
end
sendmsg(nil, 1, "首回调返回 " .. callbacks[1]() .. "，末回调返回 " .. callbacks[3]())

local function makeCounter()
    local n = 0
    return {
        inc = function() n = n + 1 end,
        get = function() return n end,
    }
end