ecmascript 6 - How to write FizzBuzz in JavaScript without using % operator - Stack Overflow

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I know how to write simple FizzBuzz code in JavaScript:

 x = 0;while (++x < 1000)console.log((x % 3 ? "" : "Fizz") + (x % 5 ? "" : "Buzz") || x);

I know how to write simple FizzBuzz code in JavaScript:

 x = 0;while (++x < 1000)console.log((x % 3 ? "" : "Fizz") + (x % 5 ? "" : "Buzz") || x);

But how can we get the same result without using the '%' operator?

• javascript
• ecmascript-6
• fizzbuzz

Share Improve this question Follow edited Feb 6, 2018 at 3:23 Peter Mortensen 31.6k2222 gold badges110110 silver badges133133 bronze badges asked Jan 14, 2018 at 5:21 Dimpu Aravind BuddhaDimpu Aravind Buddha 9,84544 gold badges1919 silver badges2323 bronze badges 1

• @NisargShah Thanks. I updated it. It's was an interview question. – Dimpu Aravind Buddha Commented Jan 15, 2018 at 21:13

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7 Answers 7

Sorted by: Reset to default 5

Think what % actually is, it is just the remainder when you divide a number by something. You can divide the number, then round the result down, then multiply it with the divisor and subtract from the number.

const mod = (num,div)=> {
    const res =  (num / div) | 0; // coerce to int
    return num - (res * div);
}

console.log(mod(8,5));

You an use Number.isInteger.

const oneToOneHundred = Array.from({ length: 100 }, (_, i) => i + 1);

const fizzBuzz = (i) => {
  if (Number.isInteger(i / 15)) return 'FizzBuzz';
  if (Number.isInteger(i / 3)) return 'Fizz';
  if (Number.isInteger(i / 5)) return 'Buzz';
  return i;
};

console.log(oneToOneHundred.map((i) => fizzBuzz(i)).join('\n'));

This is the alternative way by subtracting the number until it get negative value, then add with the divider to get the remainder.

function mod(number, divider){
	var num = number;
	while(num>=0){
		num = num - divider;
	}
	num = num + divider;
	return num;
}

console.log(mod(92, 3) == 92%3);

Here's a simple solution of fizzbuzz without modulo, and without writing your own modulo implementation. It relies on simple counters.

var i=0, n=0, f=1, b=1; 
while(i++<156)
  {
    n=i;
    
    if(f++==3)
    {
      document.write('Fizz');
      f=1; n='';
    }
    
    if(b++==5)
    {
      document.write('Buzz');
      b=1; n='';
    }
    
    document.write(n+'<br/>');
  }

We can check if the number is divisble by 3 or 5 without needing a modulo operation, or even a division operator.

If we sum all the digits, and it's either 3, 6, or 9, then the number is divisible by 3

If we check the last digit of a number, and it's either 0 or 5, then it's divisible by 5.

Code looks like so:

function isDivisibleByThree(i) {
  let sum = getDigits(i).reduce((sum, digit) => sum + digit);
  return sum > 9 ? isDivisibleByThree(sum) : (sum === 3 || sum === 6 || sum === 9);
}

function isDivisibleByFive(i) {
  let lastDigit = getDigits(i).pop();
  return lastDigit === 5 || lastDigit === 0
}

function getDigits(i) {
  return Array.from(i.toString()).map(Number);
}

for (let i = 1; i <= 100; i++) {
  let val = "";
  if (isDivisibleByThree(i))
    val += "fizz";
  if (isDivisibleByFive(i))
    val += "buzz";

  console.log(val ? val : i);
}

The Modulus operator % is simply the remainder of two numbers, you can create your own function that returns the remainder and replace it with your operator.

x = 0;

while (++x < 1000) {
  console.log((modulo(x, 3) ? "" : "Fizz") + (modulo(x, 5) ? "" : "Buzz") || x);
}

function modulo(num1, num2) {
  if (num2 === 0 || isNaN(num1) || isNaN(num2)) {
    console.log("NaN");
    return NaN;
  } else if (num2 == 1) {
    //x mod 1 always = 0
    return 0;
  }

  num1 = Math.abs(num1);
  num2 = Math.abs(num2);

  return num1 - (num2 * Math.floor((num1 / num2)));
}

Thanks everyone for your answers. I found solved it in two ways one using the hash table and by using recursion. I prefer recursion so.

function fuzzBuzz(fuzz_count,buzz_count,fuzz_buzz_count,counter) {
  if(fuzz_buzz_count === 15) {
    console.log("fuzzbuzz");
    fuzz_buzz_count = 0;
    buzz_count = 0;
    fuzz_count = 0;
  } else if(buzz_count === 5) {
    console.log("buzz");
    buzz_count = 0;
  } else if (fuzz_count === 3) {
    console.log("fuzz");
    fuzz_count = 0;
  } else  {
    console.log(counter);
  }
  
  if(counter < 100) {
    fuzzBuzz(++fuzz_count, ++buzz_count, ++fuzz_buzz_count, ++counter);
  }
  
}


fuzzBuzz(1,1,1,1);

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