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JavaScript JavaScript Loops, Arrays and Objects Simplify Repetitive Tasks with Loops Refactor Using a Loop

Posted by Adam Gheli
Adam Gheli
3,714 Points

Trying to create a loop of only even numbers from 2 - 24.

Here’s what I’m asked:

The code below logs all of the even numbers from 2 to 24 to the JavaScript console. However, there's a lot of redundant code here. Re-write this using a loop.

Here’s My Code:

var i=2;

while (i<=25) //Output the values from 0 to 10 { console.log(i + "<br>") i+2; }

script.js 
var i=2;

while (i<=25) //Output the values from 0 to 10
{
  console.log(i + "<br>")
  i+2;
}
index.html 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript Loops</title>
</head>
<body>
<script src="script.js"></script>
</body>
</html>

1 Answer

Brendan Whiting
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Brendan Whiting
Front End Web Development Techdegree Graduate 84,738 Points
Brendan Whiting
.a{fill-rule:evenodd;}techdegree seal-36
Brendan Whiting
Front End Web Development Techdegree Graduate 84,738 Points

First of all, don't worry about adding any html here ("<br>"), you're not putting content onto the page in html, you're printing to the console - the one you can view in the Chrome Developer Tools but that regular users don't see.

There's also a much easier way of selecting only even numbers using the modulus (%) operator. It gives you the remainder, so any number modulus 2 with a remainder of 0 is an even number. You can do it like this:

for (i = 1; i < 25; i++) {
  if (i % 2 === 0) {
    console.log(i);  
  }
}

I'm using a 'for' loop instead of a while loop. Not sure if that's inline with what this section was teaching, sorry if I'm confusing you.

Adam Gheli
Adam Gheli
3,714 Points

It worked like a charm. Thanks Brendan. It worked for now, but I think I'll take a moment to study how it really working. I feel so dumb transitioning from HTML to JS.