Corona 运行时错误 "attempt to concatenate field '?' (a nil value)"

Question

我在我的移动应用程序移交项目中有这个 8 个问题的调查。起初 corona 没有提示我任何错误消息，应用程序运行正常，但是当我向它添加 2 个问题时，我开始收到此消息错误我不确定为什么错误是 "a nil value" 但我的代码看起来像这样。（第 662 行到 678 行）

        function  checkEBASComplete()
        local tempScore = 0
        for i = 1, 10 do
            print("EBAS:"..ebasRating_Arr[i])
            tempScore = tempScore + ebasRating_Arr[i]

            if (ebasRating_Arr[i] == -1) then
                ebasScore = 0
                ebasScore_text.text = "Test Incomplete"
            else
                ebasScore = tempScore
                ebasScore_text.text = tostring(ebasScore)
            end

        end

        tempScore = 0
    end

    checkEBASComplete()

我在第 110 行有类似的内容。我只是在后面添加了 2 个“-1”

 local ebasRating_Arr = {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1}

有人能帮我解决这个问题吗？感谢所有帮助 :D

新问题---------------------------------------- ----------

这是我第 705 - 711 行的代码

function saveResults()

        local q = [[UPDATE EBAS_DEP SET rating1=']]..ebasRating_Arr[1] .. [[',rating2=']] .. ebasRating_Arr[2] .. [[',rating3=']] .. ebasRating_Arr[3] .. [[',rating4=']] .. ebasRating_Arr[4] .. [[',rating5=']] .. ebasRating_Arr[5] .. [[',rating6=']] .. ebasRating_Arr[6] .. [[',rating7=']] .. ebasRating_Arr[7] .. [[',rating8=']] .. ebasRating_Arr[8] .. [[',rating9=']] .. ebasRating_Arr[9] .. [[',rating10=']] .. ebasRating_Arr[10] .. [[',rating11=']] .. amtRating_Arr[1] .. [[',rating12=']] .. amtRating_Arr[2] .. [[',rating13=']] .. amtRating_Arr[3] .. [[',rating14=']] .. amtRating_Arr[4] .. [[',rating15=']] .. amtRating_Arr[5] .. [[',rating16=']] .. amtRating_Arr[6] .. [[',rating17=']] .. amtRating_Arr[7] .. [[',rating18=']] .. amtRating_Arr[8] .. [[',rating19=']] .. amtRating_Arr[9] .. [[',rating20=']] .. amtRating_Arr[10] .. [[',rating21=']] .. amtRating_Arr[11] .. [[',ebas_score=']] .. ebasScore ..[[',amt_score=']] .. amtScore ..  [['WHERE id=']].. _G.EBAS_ID..[[';]]
        db:exec( q )
        print(db:errcode(), db:errmsg())

    end

Answer 1

当您的 ebasRating_Arr 对于 checkEBASComplete 函数内的 for 循环来说太短时，就会发生错误。您原来的 table 只有 8 个条目，但您的 for 循环检查了 table 的 10 个条目。这意味着当您尝试访问 9. 条目时会发生错误，因为它不存在。

我建议将固定 for 循环从 1 to 10 更改为相对 for 循环 1 to the end of the array。这适用于 #array（或 Lua 中的 table）运算符。您的代码如下所示：

function checkEBASComplete()
    local tempScore = 0
    for i = 1, #ebasRating_Arr do       -- Changed to relative for-loop
        print("EBAS:"..ebasRating_Arr[i])
        tempScore = tempScore + ebasRating_Arr[i]
        if (ebasRating_Arr[i] == -1) then
            ebasScore = 0
            ebasScore_text.text = "Test Incomplete"
        else
            ebasScore = tempScore
            ebasScore_text.text = tostring(ebasScore)
        end
    end
    tempScore = 0
end

Corona 运行时错误 "attempt to concatenate field '?' (a nil value)"

Corona Runtime Error "attempt to concatenate field '?' (a nil value)"

lua

coronasdk