lua:遍历表中的所有对。

I have a sparse lua table and I need to iterate over it. The Problem is, it seems that lua begins the iteration at 1, and terminates as soon as it finds a nil value. Here's and example:

我有一个稀疏的lua表，我需要对它进行迭代。问题是，lua似乎在1开始迭代，一旦发现一个空值就终止。这里的例子:

> tab={}
> tab[2]='b'
> tab[5]='e'
> for i,v in ipairs(tab) do print(i,v) end
>               --nothing is output here
> tab[1]='a'
> for i,v in ipairs(tab) do print(i,v) end
1   a
2   b
>               --terminates after 2 (first nil value is tab[3])

Is there any way to get the desired output:

是否有办法得到想要的输出:

1   a
2   b
5   e

1 个解决方案

#1

You must use pairs instead of ipairs.

你必须用对而不是ipairs。

tab={}

tab[1]='a'
tab[2]='b'
tab[5]='e'

for k, v in pairs(tab) do print(k, v) end

Will output (in any order):

将输出(以任何顺序):

1   a
2   b
5   e

ipairs iterates over sequential integer keys, starting at 1 and breaking on the first nil pair.

ipairs迭代顺序整数键，从1开始，在第一个nil对上中断。

pairs iterates over all key-value pairs in the table. Note that this is not guaranteed to iterate in a specific order.

对遍历表中的所有键-值对。注意，这不能保证以特定的顺序迭代。

#1