改变函数中的变量

Question

我想做的是按下一个按钮，一堆变量发生变化。

function BuyItem(price, quantity, pps, text, quantitytext)
    if(PixoosQuantity >= price) then
        PixoosQuantity = PixoosQuantity - price
        price = price * 1.1

        quantity = quantity + 1

        PixoosPerSecond = PixoosPerSecond + pps
        PixoosPerSecondDisplay.text = "PPS: " .. string.format("%.3f", PixoosPerSecond)
        PixoosQuantityDisplay.text = "Pixoos: " .. string.format("%.3f", PixoosQuantity)

        text.text = "Deck of playing cards\nPrice: " .. string.format("%.3f", price) .. " Pixoos"
        quantitytext.text = quantity
    end
end

这是一个在按下按钮时调用的函数：

function ButtonAction(event)
    if event.target.name == "DeckOfPlayingCards" then
        BuyItem(DeckOfPlayingCardsPrice, DeckOfPlayingCardsQuantity, DeckOfPlayingCardsPPS, DeckOfPlayingCardsText, DeckOfPlayingCardsQuantityText)
    end
end

我的问题是，为什么变量不改变？我试着把 return price 之类的，但它仍然不起作用...

Answer 1

您按值而不是 by reference 传递了变量 price。此构造在 Lua 中不存在，因此您需要解决它，例如使用 return 值：

DeckOfPlayingCardsPrice, DeckOfPlayingCardsText, DeckOfPlayingCardsQuantityText = BuyItem(DeckOfPlayingCardsPrice, [...], DeckOfPlayingCardsText, DeckOfPlayingCardsQuantityText)

和return正确的期望值：

function BuyItem(price, quantity, pps, text, quantitytext)
    if(PixoosQuantity >= price) then
        [...]
    end
    return price, quantity, quantitytext
end

在 Lua 你可以 return multiple results.

改变函数中的变量

Changing variable in function

lua

coronasdk