JSFiddle - React, Tailwind, and code Playground

HTML

<script type="text/javascript" src="http://doamin.com/js/whatever.js?ref=images"></script>
<script type="text/javascript" src="http://doamin.com/js/whatever.js?ref=images&something=somethingelse"></script>

JavaScript

$("script[src*='ref=']").each(function(){
    var src=$(this).attr("src");
    var start=src.indexOf("ref=");
    var end=-1;
   
   
    if(start>0)
        end = src.indexOf("&",start+4);
    if(end==-1) end=src.length-1;    
    alert(src.substring(start+4,end));
    
});