Jitendra Zaa Blog for Javascript Utility

JSUtility.js

//Method to read parameter from query string
export function getUrlParameter(name) {
    name = name.replace(/[\[]/, '\\[').replace(/[\]]/, '\\]');
    var regex = new RegExp('[\\?&]' + name + '=([^&#]*)');
    var results = regex.exec(location.search); 
    return results === null ? '' : decodeURIComponent(results[1].replace(/\+/g, ' '));
}

JSUtility.js-meta.xml

<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>48.0</apiVersion>
    <isExposed>false</isExposed>  
</LightningComponentBundle>