FizzBuzz

A Roc solution to the popular FizzBuzz interview problem:

Print the integers from 1 to 100, replacing multiples of three with "Fizz", multiples of five with "Buzz", and multiples of both three and five with "FizzBuzz".

Code

main! = |_| {
	output =
		(1..=100)
			.map(fizz_buzz)
			|> List.from_iter
			|> Str.join_with(",")

	echo!("${output}\n")
	Ok({})
}

## Determine the FizzBuzz value for a given integer.
## Returns "Fizz" for multiples of 3, "Buzz" for
## multiples of 5, "FizzBuzz" for multiples of both
## 3 and 5, and the original number for anything else.
fizz_buzz : I32 -> Str
fizz_buzz = |n| {
	fizz = n % 3 == 0
	buzz = n % 5 == 0

	if fizz and buzz {
		"FizzBuzz"
	} else if fizz {
		"Fizz"
	} else if buzz {
		"Buzz"
	} else {
		n.to_str()
	}
}

## Test Case 1: not a multiple of 3 or 5
expect fizz_buzz(1) == "1"
expect fizz_buzz(7) == "7"

## Test Case 2: multiple of 3
expect fizz_buzz(3) == "Fizz"
expect fizz_buzz(9) == "Fizz"

## Test Case 3: multiple of 5
expect fizz_buzz(5) == "Buzz"
expect fizz_buzz(20) == "Buzz"

## Test Case 4: multiple of both 3 and 5
expect fizz_buzz(15) == "FizzBuzz"
expect fizz_buzz(45) == "FizzBuzz"

Output

Run this from the directory that has main.roc in it:

$ roc main.roc
1,2,Fizz,4,Buzz,Fizz,7,8,Fizz,Buzz,11,Fizz,13,14,FizzBuzz,16,17,Fizz,19,Buzz,Fizz,22,23,Fizz,Buzz,26,Fizz,28,29,FizzBuzz,31,32,Fizz,34,Buzz,Fizz,37,38,Fizz,Buzz,41,Fizz,43,44,FizzBuzz,46,47,Fizz,49,Buzz,Fizz,52,53,Fizz,Buzz,56,Fizz,58,59,FizzBuzz,61,62,Fizz,64,Buzz,Fizz,67,68,Fizz,Buzz,71,Fizz,73,74,FizzBuzz,76,77,Fizz,79,Buzz,Fizz,82,83,Fizz,Buzz,86,Fizz,88,89,FizzBuzz,91,92,Fizz,94,Buzz,Fizz,97,98,Fizz,Buzz

You can also use roc test to run the tests.