javascript get query parameter from url

const queryString = window.location.search;
const parameters = new URLSearchParams(queryString);
const value = parameters.get('key');

//get's a query parameter by name from current url
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, ' '));
};

//example
var userSearch=getUrlParameter('search_term');