What would be the correct way to verify if a value exists in the table in Lua?

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4

if not name in Namez do
    table.insert(Namez,name)
end

What would be the correct way to check if a name is not in the table?

lua lua-table

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2 answers

3

There’s nothing ready, you can create a function that does this, like this:

local function contains(tabela, valor)
    for i = 1, #tabela do
        if tabela[i] == valor then 
            return true
        end
    end
    return false
end

local names = {"joão", "maria", "josé"}
if not contains(names, "carlos") then
    table.insert(names, "carlos")
end
for i = 1, #names do
    print(names[i])
end

Behold working in the ideone. And in the repl it.. Also put on the Github for future reference.

1

If you want to avoid having to do a linear search for the value, you can use the names as table key

if not Namez[name] then
    Namez[name] = true
end

You can iterate the table keys with the pairs function:

for name, _ in pairs(Namez) then
    -- ...
end

Note that the pairs function does not necessarily go through things in order. If the order of names is important, you can keep a list with table.Insert simultaneously to this mapping (you can even reuse the same table for the two, if the names are all strings).

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