Change css background-Image using javascript

Question

I have an image array images having four random images,

I want to change the background-image in style of css of class contents using javascript.

for that i have created buildimage and changeImage and on onclick tried to change it .

How can i achieve it?

var images = ['https://picsum.photos/200/300/?random', 'https://picsum.photos/200/300/?random', 'https://picsum.photos/200/300/?random'];
var index = 0;

function buildImage() {
  var img = document.createElement('img');
  img.src = images[index];
  document.getElementById('content').style.background - image = (img);
}

function changeImage() {
  var img = document.getElementById('content').getElementsByTagName('img')[0];
  index++;
  index = index % 4; // This is for if this is the last image then goto first image I have 4 images so I've given 4 change accordingly 
  img.src = images[index];
}

.contents {
  width: 100px;
  height: 100px;
  border: 2px solid #FF0000;
}

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  </style>
</head>

<body onload="buildImage();">
  <div class="contents" id="content"></div>
  <button onclick="changeImage()">NextImage</button>
</body>

</html>

saAction · Accepted Answer · 2018-09-26T06:12:16.233

Problem :

You don't need to create img tag to apply background-image in CSS Style
You are applying only image path

Solution : You need to apply image path between URL() just like normal CSS background image applies

Check below code :

var images = ['https://picsum.photos/200/300/?random', 'https://picsum.photos/200/300/?random', 'https://picsum.photos/200/300/?random'];
var index = 0;

function buildImage() {
    document.getElementById('content').style.backgroundImage = 'url('+images[index]+')';
}

function changeImage() {
    index++;
    if (index >= images.length) index = 0;
    document.getElementById('content').style.backgroundImage = 'url(' + images[index] + ')';
}

.contents {
    width: 200px;
    height: 200px;
    border: 2px solid #FF0000;
}

<div class="contents" id="content"></div>
<button onclick="changeImage()">NextImage</button>

second change not happening when in system run in local system Ide — Jupiter, Sep 26 '18 at 06:14
@Jupiter, it is because of "https://picsum.photos/200/300/?random" this website, is not sending random image, while appying other images, it will work properly — saAction, Sep 26 '18 at 06:22

score 2 · Answer 2 · answered Sep 26 '18 at 05:52

Variable/property names can't have hyphens in them (the interpreter would see that as "subtraction", but that wouldn't make sense). The corresponding property for background-image in the JavaScript DOM API is backgroundImage:

function buildImage() {
  var img = document.createElement('img');
  img.src = images[index];
  document.getElementById('content').style.backgroundImage = (img);
}

score 1 · Answer 3 · answered Sep 26 '18 at 05:52

1

Change

document.getElementById('content').style.background - image = (img);

to:

document.getElementById('content').style.backgroundImage = (img);

in js, you must change first character after - to upper case. for example:

in css: border-style

in js: borderStyle

answered Sep 26 '18 at 05:52

Hassan Sadeghi

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You're welcome @Jupiter. I'm glad that was helpful :) – Hassan Sadeghi Sep 26 '18 at 06:47

Change css background-Image using javascript

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