javascript - Using Math Functions in an IF statement - Stack Overflow

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Hi I've just started to learn JavaScript. I'm doing the exercises on /. You can read it below:

FizzBuzz is a children's game where you count from 1 to 20. Easy, right?

Here's the catch: instead of saying numbers divisible by 3, say "Fizz". And instead of saying numbers divisible by 5, say "Buzz". For numbers divisible by both 3 and 5, say "FizzBuzz".

"1, 2, Fizz, 4, Buzz"...and so forth

Let's start by using console.log to print out all of the numbers from 1 and 20.

But don't type out the numbers in order—find a more awesome way!

I can get the numbers to print using a for loop but now I don't know how to replace the numbers with strings.

I thought about doing an IF statement like "if i divided by 3 is zero, then print Fizz" but I'm not sure how to do it. See what I've done so far below:

var i;
for (i = 0; i <=20; i++) {
    console.log(i);
}
if (i / 3 = 0) {
    console.log("Fizz")
}

Any help would be great.

Hi I've just started to learn JavaScript. I'm doing the exercises on http://www.codecademy./. You can read it below:

FizzBuzz is a children's game where you count from 1 to 20. Easy, right?

Here's the catch: instead of saying numbers divisible by 3, say "Fizz". And instead of saying numbers divisible by 5, say "Buzz". For numbers divisible by both 3 and 5, say "FizzBuzz".

"1, 2, Fizz, 4, Buzz"...and so forth

Let's start by using console.log to print out all of the numbers from 1 and 20.

But don't type out the numbers in order—find a more awesome way!

I can get the numbers to print using a for loop but now I don't know how to replace the numbers with strings.

I thought about doing an IF statement like "if i divided by 3 is zero, then print Fizz" but I'm not sure how to do it. See what I've done so far below:

var i;
for (i = 0; i <=20; i++) {
    console.log(i);
}
if (i / 3 = 0) {
    console.log("Fizz")
}

Any help would be great.

• javascript

Share Improve this question Follow asked Feb 4, 2012 at 19:23 CraigCraig 6911 gold badge44 silver badges1010 bronze badges 1

• Unless i is 0, i/3 cannot be 0. – kennebec Commented Feb 4, 2012 at 19:25

Add a ment  | 

5 Answers 5

Sorted by: Reset to default 3

You need to test the remainder with the modulus operator.

if (i % 3 === 0) {

The modulus operator returns the remainder after dividing the left operand by the right.

12 % 3;  // 0
13 % 3;  // 1
14 % 3;  // 2
15 % 3;  // 0

Comparisons are done with the == (or ===) operator, not =. The latter is for assignments of values to variables or object properties.

To do your if statement, then, you'd write this:

if (i / 3 === 0) {
   // ...
}

I used === because it's usually the right thing; == has some weird semantics that can be really confusing before you've gotten the hang of JavaScript.

As @kennebec notes in a ment, you may want to think through your logic again. Perhaps you want to check whether the number is divisible by three. In that case, you'd want to use the modulus operator:

if (i % 3 === 0) {
  // i is divisible by 3
}

This works:

for (i=1; i<21; i++) {

    if(i%3 === 0 && i%5 !== 0) {
        console.log("Fizz");
    } 

    else if (i%5 === 0 && i%3 !== 0) {
        console.log("Buzz");
    }

    else if (i%5 === 0 && !i%3 === 0) {
        console.log("FizzBuzz");
    }
    else {
       console.log(i); 
    }
}

var i;
for(i=1; i<=20; i++) {
    console.log(i);
    if(i % 3 === 0) {
        console.log("Fizz");    
    }
    else if(i % 5 === 0) {
        console.log("Buzz");
    }
}

Using the modulus operator will allow you to check if i is divisable with 3 or 5, as i/3 will only be 0 when i is 0. Hope this will help you proceed to your practice in javascript

Actually you're going to want something more like (i % 3 == 0).

I'm not very familiar with JavaScript so it might be a different operator, if that's the case, % means modulus. It returns the remainder of dividing to numbers. So in your case, let's say i is 3. Then i / 3 == 1, but i % 3 == 0. If i was 6, i / 3 == 2, but i % 3 == 0 still.

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