Lua函数返回问题

发布于 2024-11-24 00:57:26 字数 456 浏览 0 评论 0原文

我正在尝试用 lua 解析一些 xml 文件我被这个函数困住了：

function get_node_by_id (xml, nodeId)
    for i=1, #xml, 1 do
        if get_attr_by_name(xml[i], 'Id') == nodeId then
            print ("TRUEEEEE", i, xml[i])
            return xml[i]
        else
            get_node_by_id(xml[i], nodeId)
        end
    end
end

问题是 print("TRUEEEEE", i, xml[i]) 可以工作，但它在下一行返回 nil <代码>返回xml[i]。我做错了什么？

原文

I'm trying to parse some xml files with lua and
I'm stuck on this function:

function get_node_by_id (xml, nodeId)
    for i=1, #xml, 1 do
        if get_attr_by_name(xml[i], 'Id') == nodeId then
            print ("TRUEEEEE", i, xml[i])
            return xml[i]
        else
            get_node_by_id(xml[i], nodeId)
        end
    end
end

The problem is that print("TRUEEEEE", i, xml[i]) works, but it returns nil in the next line return xml[i].
What am I doing wrong?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

白芷 2024-12-01 00:57:26

您正在递归地调用该函数，但仅提供单个返回。如果您碰巧在第二级中找到了要查找的节点，则仅将值返回到第一级，而第一级不会对其执行任何操作。

也许你想要这样的东西（未经测试的代码）：

function get_node_by_id (xml, nodeId)
    for i=1, #xml, 1 do
        if get_attr_by_name(xml[i], 'Id') == nodeId then
            print ("TRUEEEEE", i, xml[i])
            return xml[i]
        else
            local node = get_node_by_id(xml[i], nodeId)
            if node then return node end
        end
    end
end

You are calling the function recursively, but only provide a single return. If you happen to find the node you are looking for in second level, you only return the value to first level, which doesn't do anything with it.

Maybe you want something like this (untested code):

function get_node_by_id (xml, nodeId)
    for i=1, #xml, 1 do
        if get_attr_by_name(xml[i], 'Id') == nodeId then
            print ("TRUEEEEE", i, xml[i])
            return xml[i]
        else
            local node = get_node_by_id(xml[i], nodeId)
            if node then return node end
        end
    end
end

回复收藏 0 原文