Re: How many elements in this table?
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- Subject: Re: How many elements in this table?
- From: Rici Lake <lua@...>
- Date: 2005年3月20日 20:38:18 -0500
On 20-Mar-05, at 5:25 PM, Eric Tetz wrote:
How can I tell the number of elements in table T? I'm not using it as
a list, so table.getn always returns 0. Do I need to write something
like this?
function numelements (t)
local n = 0
for k,v in t do
n = n + 1
end
return n
end
Exactly.
That seems very kludgey.
Perhaps. But why would you want to know?
The closest I usually come to this question is asking whether a table
is empty, or sometimes if it has more than one key/value pair. The
following are useful:
function is_empty(t) return next(t) == nil end
function is_multiple(t)
local first = next(t)
return next(t, first) ~= nil
end
and for what its worth
function has_at_least(t, n)
local k = nil
for i = 1, n do
k = next(t, k)
if k == nil then return false end
end
return true
end