Get URL parameters in JavaScript

getUrlParams.js

/**
 * JavaScript Get URL Parameter via https://www.kevinleary.net/javascript-get-url-parameters/
 * 
 * @param String prop The specific URL parameter you want to retreive the value for
 * @return String|Object If prop is provided a string value is returned, otherwise an object of all properties is returned
 */

function getUrlParams( prop ) {
    var params = {};
    var search = decodeURIComponent( window.location.href.slice( window.location.href.indexOf( '?' ) + 1 ) );
    var definitions = search.split( '&' );
    definitions.forEach( function( val, key ) {
        var parts = val.split( '=', 2 );
        params[ parts[ 0 ] ] = parts[ 1 ];
    } );
    return ( prop && prop in params ) ? params[ prop ] : params;
}