Jquery Fade in Fade out

Question

I have the following code:

Code:

$(document).ready(function(){
var header = $('body');

var backgrounds = new Array(
'url(/1.jpg)'
, 'url(/2.jpg)'
, 'url(/1.jpg)'

);

var current = 0;

function nextBackground() {
current++;
current = current % backgrounds.length;
header.css('background-image', backgrounds[current]);
}
setInterval(nextBackground, 5000);

header.css('background-image', backgrounds[0]);
});

What can I add to the above code so there is a "smooth" transition between background images. I prefer not to use a plugin.

THANKS :)

Answer 1

If you want to crossfade the slides, you can place a duplicate of the image on top and fade it out as the next slide changes underneath.

$(document).ready(function(){
  var image = $('.wrap');
  var fader = $('.fader');

  var backgrounds = new Array(
    'url(https://via.placeholder.com/480&text=Slide+1)'
    ,'url(https://via.placeholder.com/480&text=Slide+2)'
    ,'url(https://via.placeholder.com/480&text=Slide+3)'
  );

  var current = 0;
  function nextBackground() {
    // Change the background image while
    // creating a duplicate of image and 
    // fade it out
    fader.css('background-image', backgrounds[current]).fadeOut(function() {
      fader.css('background-image', '').show();
    });
    
    current++;
    current = current % backgrounds.length;
    
    image.css('background-image', backgrounds[current]);
  }
  setInterval(nextBackground, 2000);

  image.css('background-image', backgrounds[0]);
});

.wrap, .fader {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-size: contain;
  background-repeat: no-repeat;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="wrap">
  <div class="fader"></div>
</div>

Answer 2

You can fade it out, change the background and fade it back in:

function nextBackground() {
  current++;
  current = current % backgrounds.length;
  header.fadeOut(200, function(){
    header.css('background-image', backgrounds[current]);
    header.fadeIn(200);
  })
}