JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myClass">
    unchanged
</div>
<div id="changeMe" class="myClass">
    changed
</div>

CSS

.myClass{
    width:100px;
    height:100px;
    background-image: url(http://upload.wikimedia.org/wikipedia/commons/b/b9/Hookem_hand.gif),repeating-linear-gradient(135deg, transparent, transparent 3px, rgb(102, 102, 102) 3px, rgb(102, 102, 102) 6px), linear-gradient(rgb(51, 51, 51), rgb(153, 153, 153));
    color:white;
    text-align:center;
    position: relative;
    background-repeat: no-repeat;
    background-position: center center;
    background-color: transparent;
}

JavaScript

var elem = $("#changeMe");
var pattern = new RegExp(/url\(https?:[^,]*\)/);
var background = elem.css("background");
var replacementImage = "url(http://upload.wikimedia.org/wikipedia/commons/d/d1/Circle-question.png)";
var bgpattern = ", repeating-linear-gradient(135deg, transparent, transparent 3px, rgb(102, 102, 102) 3px, rgb(102, 102, 102) 6px), linear-gradient(rgb(51, 51, 51), rgb(153, 153, 153))";

var match = background.match(pattern);
console.log(match);

var updatedBG = background.replace(pattern,replacementImage);
console.log(updatedBG);

replacementImage = replacementImage + bgpattern;

elem.css("background-image", replacementImage);