JSFiddle - React, Tailwind, and code Playground
HTML
<div id="test">
<img src="http://neuro.amygdala.net/wp-content/uploads/2007/11/i-stress-test.gif" width="100" height="100" />
</div>
<div id="result"></div>
<div id="result2"></div>
JavaScript
$('#result').html($('#test img:first').width());
$('#result2').html($('#test img:first')[0].getAttribute('width'));