如何更改在.css中声明的背景而不是html

Question

USING JAVASCRIPT, NO JQUERY Hi all, I know this is a basic one but I am hitting a dead end. I want to change a background image that is in the .css , not the html so I cant give it an id . I managed to remove the image using:

var headerImg = document.getElementById('header').background = 'none';

And tried :

 var headerImg = document.getElementById('header').background = 'images/new-header.jpg;

But that did'nt work. I have no idea how to change the Image, and in the dev tools the url does not even change when I try to run my code Any help would be great, Thanks.

Answer 1

You're close. You're just off on the syntax slightly...

document.getElementById("header").style.backgroundImage = "url(images/new-header.jpg)";

It's a style attribute you're changing, so you need .style and then you use the CSS attribute name, but remove hyphens and camelCase the attribute name, so .backgroundImage .

Answer 2

Can you try this

 var element = document.getElementById('content'); element.style.backgroundImage = "url('https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcSzOpUTzDIq2yutn75PQTLcHhJ06MTZPsV_V-0M918xKUhAqMxE')"; 

 <div> <p>this is unchanged</p> <p id="content">backgroud wiil be cange</p> <div>