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We start by putting the images on the webpage,
and assigning them a class. -->

<img class="bg" src="">
<img class="bg" src="">
<img class="bg" src="">




                // select all objects of the class
var backgrounds = document.querySelectorAll('.bg');

// apply an eventlistener which listens for "hover" or mouseover events
// when an image is hovered over, the changeBackground function executes
backgrounds.forEach((bg) => {
  bg.addEventListener('mouseover', changeBackground);

function changeBackground() {
  // "this" refers to the image being hovered over
  // we can get the URL of the image this way
  var imageURL = this.getAttribute('src');
  // then we change the body's background to the URL = 'url(' + imageURL + ')';