JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.3/jquery.min.js"></script>
<img src="http://2.bp.blogspot.com/-1lsXAuaZ5Cs/VLi5g8nQTmI/AAAAAAAACEs/KZdJRzgVP9Q/s1600/javascript-logo-png.png" id="test" style="float: left;" />

JavaScript

$(document).ready(function(){
if( $('#test').css('float') != 'none' && typeof($('#test')) != 'undefined'){
	alert ("obrazek z flotami - float: " + $("#test").css("float"));
} else {
alert("Obrazek nie flotuje - float: " + $("#test").css("float"));
}
	
})