print(fizz..buzz)

Question

I couldn't help but notice we didn't have a FizzBuzz in lua yet. I've always wanted to take a shot at Lua, so here goes nothing.

Code:

function fizzBuzz(maxNum)
  local fizz = "Lua"
  local buzz = "Yay"
  for i = 1, maxNum do
    if i % 15 == 0 then
      print(fizz..buzz)
    elseif i % 3 == 0 then
      print(fizz)
    elseif i % 5 == 0 then
      print (buzz)
    else
      print(i)
    end
  end
end

fizzBuzz(100)

Output:

1
2
Lua
4
Yay
Lua
7
8
Lua
Yay
11
Lua
13
14
LuaYay
16
17

I highly doubt it's idiomatic Lua, so I'm open for suggestions. As far as I know mixedCase and 2-space indentation are the way to go for Lua, but feel free to prove me wrong.

Answer 1

Lua, by definition is an embeddable scripting language. So, there are no guidelines as to how you want to create a variable or indent your code. It largely is a factor of how a developer feels comfortable.

Please note that although there is a style guide available for Lua, it actually is an amalgamation of Python, Perl, C and C++ style guides.

Two things, which I have seen common among a lot of lua programs/modules is that the function names (if not defined as a method of an object) are defined in snake_case, and if defined as a method to an object, use CamelCase (with both C capitalised). And another is, the variables for general data-types (number, string, function, table, boolean) follow a Hungarian notation.

In your fizzbuzz, when calling the print function, you have given an extra space for the buzz output, whereas nothing as such for others. Keeping it consistent:

if i % 15 == 0 then
  print(fizz..buzz)
elseif i % 3 == 0 then
  print(fizz)
elseif i % 5 == 0 then
  print(buzz)    -- remove whitespace
else
  print(i)
end

You could also store the fizz..buzz value outside of the loop, just to avoid one extra calculation. Apart from that everything looks good.

Answer 2

While hjpotter92 is correct about it being up to the programmers, I can offer improvements upon your code:

local fizz = "Lua"
local buzz = "Yay"
--Keeping them out of scope means the function isn't redeclaring them each time it's run
function fizzBuzz(maxNum)
   for i = 1, maxNum do
      print(i%15==0 and fizz..buzz or i%5==0 and buzz or i%3==0 and fizz or i)
      --By using Lua's logical operators you can cut down on massive chunks of code like the if statements you had made
   end
end

fizzBuzz(100)

Answer 3

Lua logical operators work a bit uniquely, so one can do:

function fizzbuzz(num)
  return
      num%15 == 0
      and 'fizzbuzz'
    or
      num%5 == 0
      and 'fizz'
    or
      num%3 == 0
      and 'buzz'
    or
      tostring(num)
end

for i = 1,100 do
  print(fizzbuzz(i))
end

Notice, this is literally the same as the previous answer, only formatted differently.

I love to use this style to describe logic, it is extremely easy to read.