How do I get first table value in Lua

Question

Is there an easier way to do this? I need to get the very first value in a table, whose indexes are integers but might not start at [1]. Thx!

local tbl = {[0]='a',[1]='b',[2]='c'}  -- arbitrary keys
local result = nil
for k,v in pairs(tbl) do -- might need to use ipairs() instead?
    result = v
    break
end

Solution

If the table may start at either zero or one, but nothing else:

if tbl[0] ~= nil then
    return tbl[0]
else
    return tbl[1]
end

-- or if the table will never store false
return tbl[0] or tbl[1]

Otherwise, you have no choice but to iterate through the whole table with pairs, as the keys may no longer be stored in an array but rather in an unordered hash set:

local minKey = math.huge
for k in pairs(tbl) do
    minKey = math.min(k, minKey)
end

Comments

[greatwolf]

The ternary and or above doesn't avoid the falsey caveat, eg. tble[0] == false. You'll have to switch it around tbl[0] == nil and tbl[1] or tbl[0].

[ryanpattison]

tbl = {false} will give nil instead of false. Probably not problematic but not that obvious.

[mallwright]

Why not use ipairs for this?