JSFiddle - React, Tailwind, and code Playground
HTML
<div id="data">
<div class="img"><img src="imageurl_1"></div>
<div class="img"><img src="imageurl_2"></div>
<div class="img"><img src="imageurl_3"></div>
<div class="img"><img src="imageurl_4"></div>
</div>
JavaScript
var urls = '';
urls = urls + ' ' + $('#data').html();
alert(urls);