Re: How to determine true size of a table?
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- Subject: Re: How to determine true size of a table?
- From: Tyranni <tyranni@...>
- Date: 2006年3月03日 11:14:43 -0500
If you have control of the construction of the table, you can keep a count yourself the whole time
using techniques like this:
http://www.lua.org/pil/13.4.4.html
That example tracks all accesses, but you could easily modify it to only track non-integer inserts.
Adam D. Moss wrote:
> Matt Campbell wrote:
>
>> The only way I know to count non-indexed values in a table is like this:
>>
>> function countFields(t)
>> local count = 0
>> for k, v in pairs(t) do
>> count = count + 1
>> end
>> return count
>> end
>>
>> Does anyone have a better solution?
>
>
> The above will count all values, not just non-integer-index
> parts of the table. The length operator will also not be
> useful where the integer-index parts of the table are
> sparse.
>
> I guess something like this is what's wanted:
>
>> function countFields(t)
>> local count = 0
>> for k, v in pairs(t) do
>> count = count + 1
>> end
>> for k, v in ipairs(t) do
>> count = count - 1
>> end
>> return count
>> end
>
> (brr!!!)
>
> --adam
>