freecodecamp--freecodecamp/curriculum/challenges/english/blocks/daily-coding-challenges-javascript/69b58ce40693f140c84c855a.md

id, title, challengeType, dashedName

id	title	challengeType	dashedName
69b58ce40693f140c84c855a	Challenge 241: FizzBuzz Validator	28	challenge-241

--description--

Given an array of sequential integers, with multiples of 3 and 5 replaced, determine if it's a valid FizzBuzz sequence.

In a valid FizzBuzz sequence:

• Multiples of 3 are replaced with "Fizz".
• Multiples of 5 are replaced with "Buzz".
• Multiples of both 3 and 5 are replaced with "FizzBuzz".
• All other numbers remain as integers.

--hints--

isFizzBuzz([1, 2, "Fizz", 4, "Buzz"]) should return true.

assert.isTrue(isFizzBuzz([1, 2, "Fizz", 4, "Buzz"]));

isFizzBuzz([13, 14, "FizzBuzz", 16, 17]) should return true.

assert.isTrue(isFizzBuzz([13, 14, "FizzBuzz", 16, 17]));

isFizzBuzz([1, 2, "Fizz", 4, 5]) should return false.

assert.isFalse(isFizzBuzz([1, 2, "Fizz", 4, 5]));

isFizzBuzz(["FizzBuzz", 16, 17, "Fizz", 19, "Buzz"]) should return true.

assert.isTrue(isFizzBuzz(["FizzBuzz", 16, 17, "Fizz", 19, "Buzz"]));

isFizzBuzz([1, 2, "Fizz", "Buzz", 5]) should return false.

assert.isFalse(isFizzBuzz([1, 2, "Fizz", "Buzz", 5]));

isFizzBuzz([97, 98, "Buzz", "Fizz", 101, "Fizz", 103]) should return false.

assert.isFalse(isFizzBuzz([97, 98, "Buzz", "Fizz", 101, "Fizz", 103]));

isFizzBuzz(["Fizz", "Buzz", 101, "Fizz", 103, 104, "FizzBuzz"]) should return true.

assert.isTrue(isFizzBuzz(["Fizz", "Buzz", 101, "Fizz", 103, 104, "FizzBuzz"]));

--seed--

--seed-contents--

function isFizzBuzz(arr) {

  return arr;
}

--solutions--

function isFizzBuzz(arr) {
  let start = null;
  for (let i = 0; i < arr.length; i++) {
    if (typeof arr[i] === "number") {
      start = arr[i] - i;
      break;
    }
  }

  if (start === null) return false;

  for (let i = 0; i < arr.length; i++) {
    const n = start + i;
    const expected = n % 15 === 0 ? "FizzBuzz" : n % 3 === 0 ? "Fizz" : n % 5 === 0 ? "Buzz" : n;
    if (arr[i] !== expected) return false;
  }

  return true;
}