Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community!

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript Loops Working with 'for' Loops The Refactor Challenge – One Solution

Gal Parselany
.a{fill-rule:evenodd;}techdegree seal-36
Gal Parselany
Front End Web Development Techdegree Graduate 19,383 Points

My solution is good aswell? I dont use the let before the for loops, but only inside the for loops. is that ok?

let html = '';
for (i = 1; i <= 10; i++) {
    let red = Math.floor(Math.random() * 256);
    let green = Math.floor(Math.random() * 256);
    let blue = Math.floor(Math.random() * 256);
    let randomRGB = `rgb( ${red}, ${green}, ${blue} )`;
    html += `<div style="background-color: ${randomRGB}">${i}</div>`;
document.querySelector('main').innerHTML = html;

is that ok too? cause I see that Guil is still using the vars outside the for loops, and I dont understand if its necessary. thanks in advance

1 Answer

Steven Parker
Steven Parker
224,848 Points

By declaring the variables outside the loop, Guil's code inside the loop becomes a simple assignment making the loop more efficient.

Declaring the variables inside the loop will do the same job, but they will be disposed and then re-created for each iteration, using a bit more processor time. But since the loop is simple and short, the difference won't be noticed.