Why does the 'output' variable in this code get reset every iteration?

Question

0.00/5 (No votes)

See more:

Hi guys, I'm reading a JS book at the moment and one of the challenges had us loop over all integers between 1 - 100 and write "Fizz" if it's divisible by 3, "Buzz" if it's divisible by 5 and "FizzBuzz" if it's divisible by both, otherwise just log the number. I managed to work out the code for the problem but I'm unsure as to why the 'output' declaration gets reset every iteration rather than storing a long line of Fizzes and Buzzes. Here's the code:

for (let num = 1; num <= 100; num++){
	let output = "";
	if(num % 3 == 0) output += "Fizz";
	if(num % 5 == 0) output += "Buzz";
	console.log(output || num);
    }

What I have tried:

I've tried googling the question but I can't find anything specific as to why a variable sometimes resets each iteration, whereas sometimes it gets stored over and over to concatenate everything.

Posted 5-Jul-18 2:24am

Member 13899723

Updated 5-Jul-18 2:34am

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

User 7429338 · Accepted Answer · 2018-07-05T02:34:00

Solution 1

It's because you declare it inside the loop. Declare it outside the loop to concatenate each iteration:

let output = "";
for (let num = 1; num <= 100; num++){
	if(num % 3 == 0) output += "Fizz";
	if(num % 5 == 0) output += "Buzz";
	console.log(output || num);
}

Posted 5-Jul-18 2:34am

User 7429338

Comments

Member 13899723 5-Jul-18 8:45am

@Thaddeus Jones Ahhh that makes sense, every time it loops it sets the value to "" again, whereas if it were outside the loop it wouldn't get reset as it's not beeing reevaluated... Thanks for the clarity :)

CPallini 5-Jul-18 9:00am

5.