JSFiddle - React, Tailwind, and code Playground

JavaScript

var URLParser = function (url) {
    this.url = url || window.location.href;
    this.urlObject = this.parse(); 
};

URLParser.prototype = {
    constructor : URLParser,
    
    parse : function (url) {
        var tempArr,
            item,
            i,
            returnObj = {};
        this.url = url || this.url;
        tempArr = this.url.split("?");
        returnObj.baseURL = tempArr[0];
        returnObj.params = {};
        if (tempArr.length > 1) {
            returnObj.queryString = tempArr[1];
            tempArr = tempArr[1].split("&");
            for (i = 0; i < tempArr.length; i++) {
                item = tempArr[i].split("=");
                returnObj.params[item[0]] = item[1];    
            }
        } else {
            returnObj.queryString = "";
        }
        
        return returnObj;
    },
    
    toString : function () {
        var strURL = this.urlObject.baseURL + "?",
            paramObj = this.urlObject.params,
            prop;
        for (prop in paramObj) {
            if (paramObj.hasOwnProperty(prop)) {
                strURL += prop + "=" + paramObj[prop] + "&";
            }
         }
        return strURL.substr(0, strURL.length - 1);
    },
    
    removeParams : function (removeArray) {
        var paramObj = this.urlObject.params,
            key,
            i;
        if (removeArray instanceof Array) {
            for (i = 0; i < removeArray.length; i++) {
                key = removeArray[i];
                if (paramObj.hasOwnProperty(key)) {
                    delete paramObj[key];
                }
            }
        }
    },
    
    addParams : function (paramObj) {
        var params = this.urlObject.params,
            key;
        if (typeof paramObj === "object") {
            for (key in paramObj) {
                if (paramObj.hasOwnProperty(key)) {
                    params[key] = paramObj[key];
                }
            }
        }
    }
};

var up = new URLParser();
var urlObj =...