Lua: print integer as a binary

Question

How can I represent integer as Binary?

so I can print 7 as 111

Answer 1

Here is a function inspired by the accepted answer with a correct syntax which returns a table of bits in wriiten from right to left.

num=255
bits=8
function toBits(num, bits)
    -- returns a table of bits
    local t={} -- will contain the bits
    for b=bits,1,-1 do
        rest=math.fmod(num,2)
        t[b]=rest
        num=(num-rest)/2
    end
    if num==0 then return t else return {'Not enough bits to represent this number'}end
end
bits=toBits(num, bits)
print(table.concat(bits))

>>11111111