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javascript - Dynamically Changing CSS Background Image

What I'm looking for is a way to make my HTML header tag change background images every few seconds. Any solutions are welcome, as long as it is not to complex.

I have this code right now as well as linking to JQuery:

<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>

$(function() {
    var header = $(‘.mainHeader’);
    var backgrounds = new Array(
        ‘url(img/rainbow.jpg)’,
        ‘url(img/chickens_on_grass.jpg)’
        ‘url(img/cattle_on_pasture.jpg)’
        ‘url(img/csa_bundle.jpg)’
    );
    var current = 0;

    function nextBackground() {
        header.css(‘background’,backgrounds[current = ++current % backgrounds.length]);
        setTimeout(nextBackground, 10000);
    }

    setTimeout(nextBackground, 10000);
    header.css(‘background’, backgrounds[0]);
});

My HTML header:

<header class="mainHeader"></header>

And CSS:

.mainHeader {
    background: no-repeat center bottom scroll; 
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    min-height: 150px;
    padding-top: 2%;
    font-size: 100%;
}

Right now I have now background image at all.

See Question&Answers more detail:os

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1 Reply

0 votes
by (71.8m points)

Made a few amendments to your code

DEMO: http://jsfiddle.net/p77KW/

var header = $('body');

var backgrounds = new Array(
    'url(http://placekitten.com/100)'
  , 'url(http://placekitten.com/200)'
  , 'url(http://placekitten.com/300)'
  , 'url(http://placekitten.com/400)'
);

var current = 0;

function nextBackground() {
    current++;
    current = current % backgrounds.length;
    header.css('background-image', backgrounds[current]);
}
setInterval(nextBackground, 1000);

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

Biggest changes (as noted in others comments) is that you have to use apostrophe**'**s, not those funky open and close single-quotes and that your array wasn't correct.

With these corrections out of the way I simplified a few things:

  1. Increment current then take modulus (I know this is basically what you did but how much easier is that to debug ;))
  2. Target background-image directly
  3. Used setInterval() instead of a double call to setTimeout

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