title: How to set CSS style property in JavaScript with fallback?
body: <p>In CSS, I have e.g. the following:</p>
  <pre><code>background-image: url(&quot;IMAGE_URL&quot;); /* fallback */
  background-image: url(&quot;IMAGE_URL&quot;), linear-gradient(#eb01a5, #d13531); /* W3C */
  </code></pre>
  <p>I want to achieve the same effect in JavaScript. I.e. I want to set the backgroundImage property, but I also want to set a fallback. But element.style.backgroundImage does not accept a string array.</p>
  <pre><code>element.style.backgroundImage = 'url(&quot;IMAGE_URL&quot;), linear-gradient(#eb01a5, #d13531)'; // How to include the fallback here?
  </code></pre>
  <p>I don't want to use hacks to check which browser the user is using. If it's not possible, I would also like to know.</p>