How to get index of dictionary?

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#1

How do I get the index of a dictionary? I can’t come up with anything

local tbl = {
["A"] = 1,
["B"] = 4,
}

print(tbl["A"]) -- prints 1, how can I make it print A?
#2

Few ways to do this. You could create a separate array called tblInverse in which all of the keys are the same values, then set a metatable to tblInverse to have new indices set when tbl has new indices set.

Here is some example code without the metatable because that is just for some extra functionality.

local tbl = {
    ["A"] = 1,
    ["B"] = 4
}

local function createInverseTable(tbl)
    local inverse = {}

    for i, v in pairs(tbl) do
        inverse[v] = i
    end

    return inverse
end

local tblInverse = createInverseTable(tbl)

print(tblInverse[4]) --// Outputs B
print(tblInverse[1]) --// Outputs A

Alternatively try implementing your own find function using a linear search.

local function find(tbl, value)
    for i, v in pairs(tbl) do
        if (v == value) then
            return i
        end
    end
end

local tbl = {
    ["A"] = 1,
    ["B"] = 4
}

print(find(tbl, 4)) --// Outputs A
print(find(tbl, 1)) --// Outputs B
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#3

What @EpicMetatableMoment said might work but I have an easier solution for you

You can try this:

local tbl = {
["A"] = 1,
["B"] = 4,
}


for i, v in pairs(tbl) do -- getting the for i, v in pairs loop to print A
	print(i) 
	if i == "A" then -- if it's A then don't print anything else
		break
	end
end

This is easier to understand than what he said and should work perfectly.

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