Learn Basic Debugging by Building a Random Background Color Changer - Step 8

JavaScript
1

Tell us what’s happening:

I can’t understand what I need to do in this step, if we refer to changing the background color we have a button btn that uses the onclick method that when pressed launches the color change function

Your code so far

<!-- file: index.html -->
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Build a random background color changer</title>
    <link rel="stylesheet" href="./styles.css" />
  </head>
  <body>
    <h1>Random Background Color changer</h1>

    <main>
      <section class="bg-information-container">
        <p>Hex Code: <span id="bg-hex-code">#110815</span></p>
      </section>

      <button class="btn" id="btn">Change Background Color</button>
    </main>
    <script src="./script.js"></script>
  </body>
</html>

/* file: script.js */
const darkColorsArr = [
  "#2C3E50",
  "#34495E",
  "#2C2C2C",
  "#616A6B",
  "#4A235A",
  "#2F4F4F",
  "#0E4B5A",
  "#36454F",
  "#2C3E50",
  "#800020",
];

function getRandomIndex() {
  const randomIndex = Math.floor(darkColorsArr.length * Math.random());
  return randomIndex;
}

const body = document.querySelector("body");
const bgHexCodeSpanElement = document.querySelector("#bg-hex-code");

function changeBackgroundColor() {
  const color = darkColorsArr[getRandomIndex()];

  bgHexCodeSpanElement.innerText = color;
  body.style.backgroundColor = color;
}
const btn = document.querySelector("#btn");


// User Editable Region

btn.onclick = changeBackgroundColor();

// User Editable Region


/* file: styles.css */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --yellow: #f1be32;
  --golden-yellow: #feac32;
  --dark-purple: #110815;
  --light-grey: #efefef;
}

body {
  background-color: var(--dark-purple);
  color: var(--light-grey);
  text-align: center;
}

.bg-information-container {
  margin: 15px 0 25px;
  font-size: 1.2rem;
}

.btn {
  cursor: pointer;
  padding: 10px;
  margin: 10px;
  color: var(--dark-purple);
  background-color: var(--golden-yellow);
  background-image: linear-gradient(#fecc4c, #ffac33);
  border-color: var(--golden-yellow);
  border-width: 3px;
}

.btn:hover {
  background-image: linear-gradient(#ffcc4c, #f89808);
}

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Challenge Information:

Learn Basic Debugging by Building a Random Background Color Changer - Step 8

2

The presence of the parenthesis here makes this a function call and not a function reference. Remove them to make the event trigger the function when the click happens.

3

that is, when using a function without parentheses, we call it by reference ?

4

We are not calling it at all when we just write the name down without the paren. Instead we are providing a reference to it for later invocation.

5

ooooohhhh got it, thx

1 Like