错误:尝试索引字段“?" (零值) [英] Error: attempt to index field '?' (a nil value)
问题描述
我的Lua代码出现以下错误:
I get the following error in my Lua code:
试图索引字段?" (零值)
attempt to index field '?' (a nil value)
它在下面的行中以粗体显示.我该如何解决?
It happens on the line below in bold. How can I fix it?
function SendMessageToAdmins(color1, color2, color3, msg)
for i = 0, maxSlots - 1 do
if Account[i] and Account[i].Admin >= 1 or Account[i] and Account[i].GameMaster >= 1 then
SendPlayerMessage(i, color1, color2, color3, string.format("%s", msg))
end
end
end
推荐答案
此错误通常是由于试图为不是表或nil的对象上的字段建立索引而引起的.发生错误时,出现在Account[i]
处的不是表或用户数据,而是诸如字符串或数字之类的内置类型.
this error usually comes from trying to index a field on something that isn't a table, or nil. chances are that whatever is at Account[i]
when the error happens, isn't a table or userdata, but a built in type like a string or number.
从出现错误时检查Account[i]
中任何内容的类型开始,然后从那里开始.
i'd start with checking the type of whatever is in Account[i]
when you get that error, and going from there.
以下是我知道的两种最常见的查看此错误的方法:
the two most common ways to see this error (that i know of) are below:
local t = { [1] = {a = 1, b = 2}, [2] = {c = 3, d = 4} }
-- t[5] is nil, so this ends up looking like nil.a which is invalid
-- this doesn't look like your case, since you check for
-- truthiness in Account[i]
print(t[5].a)
您可能遇到的情况很可能是以下情况:
the case you are probably experiencing, is most likely this one:
local t =
{
[1] = {a = 1, b = 2},
[2] = 15, -- oops! this shouldn't be here!
[3] = {a = 3, b = 4},
}
-- here you expect all the tables in t to be in a consistent format.
-- trying to reference field a on an int doesn't make sense.
print(t[2].a)
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