创建Lua高级表

发布于 2024-11-24 20:45:06 字数 679 浏览 0 评论 0原文

需要创建一些表，以便我可以通过以下方式从中获取信息：

table[attacker][id]

如果我使用

print(table[attacker][id])

它，它应该打印值。

尝试了很多方法，但没有找到任何好的...

我想它应该是这样的...

table.insert(table, attacker, [id] = value)

^这不起作用。

有人可以帮助我吗？

编辑

好吧，当我尝试这种方式时：

x = {}
function xxx()
    if not x[attacker][cid] then
        x[attacker][cid] = value
    else
        x[attacker][cid] = x[attacker][cid] + value
    end
    print(x[attacker][cid])
end

我收到一条错误消息：

尝试索引字段“?” （零值）

原文

Need to create some table so I can get an info from it in this way:

table[attacker][id]

And if I'll use

print(table[attacker][id])

It should print the value.

Tried many ways, but haven't found any good ...

I guess it should be something like this...

table.insert(table, attacker, [id] = value)

^ This does not work.

Can someone help me?

Edit

Well, when I try it this way:

x = {}
function xxx()
    if not x[attacker][cid] then
        x[attacker][cid] = value
    else
        x[attacker][cid] = x[attacker][cid] + value
    end
    print(x[attacker][cid])
end

I get an error saying:

attempt to index field '?' (a nil value)

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江湖彼岸 2024-12-01 20:45:06

您需要花括号来创建内部表：

table.insert(my_table, attacker, {[id]=value})

或

-- the advantage of this is that it works even if 'attacker' isn't a number
my_table[attacker] = {[id]=value}

a = 1
b = 2
c = 3
d = {}
table.insert(d, a, {[b]=c})
print(d[a][b]) -- prints '3'

You need the curly braces to create the inner table:

table.insert(my_table, attacker, {[id]=value})

-- the advantage of this is that it works even if 'attacker' isn't a number
my_table[attacker] = {[id]=value}

a = 1
b = 2
c = 3
d = {}
table.insert(d, a, {[b]=c})
print(d[a][b]) -- prints '3'

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孤芳又自赏 2024-12-01 20:45:06

什么是攻击者？也就是说，它包含什么价值？它包含什么并不重要，因为 Lua 表可以使用任何 Lua 值作为键。但了解一下会有用。

无论如何，这真的很简单。

tableName = {}; --Note: your table CANNOT be called "table", as that table already exists as part of the Lua standard libraries.
tableName[attacker] = {}; --Create a table within the table.
tableName[attacker][id] = value; --put a value in the table within the table.

您编辑中出现的问题是因为您没有注意上面的步骤 2。 Lua 表中的值在有值之前都是空的 (nil)。因此，直到第 2 行，tableName[attacker] 为nil。您不能对 nil 值建立索引。因此，您必须确保您希望索引到的tableName 中的任何键实际上都是表。

换句话说，除非您知道 type(tableName[attacker]) == "table"<，否则您无法执行tableName[attacker][id] /代码> 是正确的。

What is attacker? That is, what value does it contain? It doesn't really matter what it contains since Lua tables can use any Lua value as a key. But it would be useful to know.

In any case, it's really simple.

tableName = {}; --Note: your table CANNOT be called "table", as that table already exists as part of the Lua standard libraries.
tableName[attacker] = {}; --Create a table within the table.
tableName[attacker][id] = value; --put a value in the table within the table.

The problem in your edit happened because you didn't take note of step 2 above. Values in a Lua table are empty (nil) until they have a value. Therefore, until line 2, tableName[attacker] is nil. You cannot index a nil value. You therefore must ensure that any keys in tableName that you expect to index into are in fact tables.

To put it another way, you cannot do tableName[attacker][id] unless you know that type(tableName[attacker]) == "table" is true.

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