从我的Div背景图像属性中循环播放3张图像

Question

I have a code to loop images but based on an Img source, but how to improve it to make it work for the "background-image" property of a div?

HTML

<div id="section2"></div>   

CSS

#section2 {
background-image: 'url(..images/banner1.jpg');
} 

JAVASCRIPT

<script type = "text/javascript">
(function() {     
var i = 1;
var pics = [ "images/banner1.jpg", "images/banner2.jpg", "images/banner3.jpg" ];
var el = document.getElementById('section2');  
function toggle() {
    el.src = pics[i];           
    i = (i + 1) % pics.length;  
}
setInterval(toggle, 3000);
})();             
  </script>

Thanks in Advance :)

Answer 1

One way would be to use CSS classes instead of sources.

JS:

<script type = "text/javascript">
(function() {     
var i = 1;
var classes = [ "bgd-1", "bgd-2", "bgd-3" ]; // adjusted
var el = document.getElementById('section2');  
function toggle() {
    el.className = classes[i]; // adjusted           
    i = (i + 1) % classes.length; // adjusted 
}
setInterval(toggle, 3000);
})();             
</script>

CSS:

#section2.bgd-1 {
    background-image: url('..images/banner1.jpg');
} 

#section2.bgd-2 {
    background-image: url('..images/banner2.jpg');
} 

#section2.bgd-3 {
    background-image: url('..images/banner3.jpg');
} 

Note:

Use el.className += ' ' + classes[i]; to append a class name instead of replacing all element classes.