Lua: print integer as a binary

Question

How can I represent integer as Binary?

so I can print 7 as 111

Answer 1

This maybe not work in lua that has no bit32 library

    function toBinary(number, bits)
        local bin = {}
        bits = bits - 1
        while bits >= 0 do --As bit32.extract(1, 0) will return number 1 and bit32.extract(1, 1) will return number 0
                       --I do this in reverse order because binary should like that
            table.insert(bin, bit32.extract(number, bits))
            bits = bits - 1
        end
        return bin
    end
    --Expected result 00000011
    print(table.concat(toBinary(3, 8)))

This need at least lua 5.2 (because the code need bit32 library)