How do I change the background image every X seconds?

Question

I have a div that fills the entirety of a page (portfolio style). The div has this style:

.image-head {
  background: url('http://placehold.it/1920x1080') no-repeat top center fixed;
  background-size: cover;
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
  color: black;
  text-align: center;
}

Basically, what I want to do is every X seconds change the url that the div points to for it's background image, but I am unsure on how to do this.

My markup currently looks like this:

<div class="image-head">
  <div class="centering-hack">
    <h1>Something HTML</h1>
  </div>
</div>

What's the simplest/best solution here?

Thanks!

Edit: I'm using Bootstrap 3 if the JS library makes anything easier

Answer 1

Make an array with the images you want to use:

var images = [
  "https://www.royalcanin.com/~/media/Royal-Canin/Product-Categories/cat-adult-landing-hero.ashx",
  "https://www.petfinder.com/wp-content/uploads/2013/09/cat-black-superstitious-fcs-cat-myths-162286659.jpg",
  "https://upload.wikimedia.org/wikipedia/commons/4/4d/Cat_March_2010-1.jpg"
]

We retrieve the div whose background you want to change:

var imageHead = document.getElementById("image-head");

You can now use setInterval to change the background image url every second (or whatever interval you want):

var i = 0;
setInterval(function() {
      imageHead.style.backgroundImage = "url(" + images[i] + ")";
      i = i + 1;
      if (i == images.length) {
        i =  0;
      }
}, 1000);

Here's a live example: https://jsfiddle.net/vvwcfkfr/1/

Some improvements using functional programming, ES6 and recursiveness:

const cats = [
  "https://www.royalcanin.com/~/media/Royal-Canin/Product-Categories/cat-adult-landing-hero.ashx",
  "https://www.petfinder.com/wp-content/uploads/2013/09/cat-black-superstitious-fcs-cat-myths-162286659.jpg",
  "https://upload.wikimedia.org/wikipedia/commons/4/4d/Cat_March_2010-1.jpg"
]

const node = document.getElementById("image-head");

const cycleImages = (images, container, step) => {
    images.forEach((image, index) => (
    setTimeout(() => {
        container.style.backgroundImage = `url(${image})`  
    }, step * (index + 1))
  ))
  setTimeout(() => cycleImages(images, container, step), step * images.length)
}

cycleImages(cats, node, 1000)

https://jsfiddle.net/du2parwq/