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JavaScript JavaScript Loops Working with 'for' Loops The Refactor Challenge – Duplicate Code

Couldn't get the code to run while working along this Loops video. Please let me know what I am doing wrong.

let html = '';
let red;
let green;
let blue;
let randomRGB;

const randomValue = () => Math.floor(Math.random() * 256);

function randomRGB(value) {
const color = `rgb( ${value()}, ${value()}, ${value()} )`;
return color;
}

for (let i = 1; i <=10; i++ ) {

  red = randomValue();
green = randomValue();
blue = randomValue();
randomRGB = `rgb( ${red}, ${green}, ${blue} )`;
html += `<div style="background-color: ${randomRGB(randomValue)}">${i}</div>`;

}
document.querySelector('main').innerHTML = html;

Mod edit: Added markdown formatting for code readability. Check out the "Markdown Cheatsheet" linked below the comment box for tips on how to format your code for the forums.

Your code contains parts of an old solution in the video in addition to the final solution. This causes you to attempt to use the same variable name for different purposes: You have declared the variable name 'randomRGB' on line 5 (from old solution), but you use the same name to declare a function on line 9 (from final solution). On line 19 it shows up as a variable again (from old solution), and on line 20 it is used as a function call (from final solution).

If you comment out line 5 and 19 (add // at the start of the lines) your code works!! Though you will have some unused code hanging around (refering to the red, green and blue variable occurances).

1 Answer

Your code looks like it's missing string interpolation backtics in a few places. Remember, anywhere you are using ${}, it must be wrapped in backticks.

ex.

`rgb( ${value}, ${value}, ${value} )`;

Also, some of the code that got refactored in this lesson is still included in your script here. I've commented the things that should be removed.

I've just changed the spacing for readability

let html = '';
let red;
let green;
let blue;

// you can't have a function called randomRGB if you've already declared it as a variable
// let randomRGB;

const randomValue = () => Math.floor(Math.random() * 256);

function randomRGB(value) {
    // for ${} to work, you need to use string interpolation (wrap your string in backticks)
    const color = `rgb( ${value()}, ${value()}, ${value()} )`;
    return color; 
}

for (let i = 1; i <=10; i++ ) {
    // randomValue has been updated to automatically generate the three random numbers for red, green and blue
    // these bits of code were used earlier in this lesson, but aren't in use here, so you can remove all of these

    // red = randomValue(); 
    // green = randomValue(); 
    // blue = randomValue(); 
    // randomRGB = rgb( ${red}, ${green}, ${blue} ); 

    // added backticks here as well
    html += `<div style="background-color: ${randomRGB(randomValue)}">${i}</div>`;
}

document.querySelector('main').innerHTML = html;
Cameron Childres
Cameron Childres
Treehouse Moderator 11,719 Points

Great answer, thanks John! All I have to add is that the backticks are present but were obscured by the forum's markdown rules. I've gone ahead and edited the original post to add code formatting so they show up appropriately.

For anyone else reading this that may be unfamiliar, be sure to check out the "Markdown Cheatsheet" linked below the comment box for examples of how to make your code display properly in the community.