Some simple functions to manipulate URL params using JavaScript

urlParams.js

function goTo(href) {		
  if (!href) { return false; }		
  		
  return window.location.href = href;		
}

function getUrlParam (key) {
  var paramsAssoc = getUrlParamsAssoc();

  return (undefined == paramsAssoc[key]) ? null : paramsAssoc[key];
};

function addUrlParam (key, value) {
  var paramsAssoc = getUrlParamsAssoc();
  paramsAssoc[key] = value;

  return buildUrlViaParams(paramsAssoc);
};

function removeUrlParam (key) {
  var paramsAssoc = getUrlParamsAssoc();

  if (undefined != paramsAssoc[key]) {
    delete paramsAssoc[key];
  }

  return buildUrlViaParams(paramsAssoc);
};

function buildUrlViaParams (paramsAssoc, urlObject) {
      urlObject = (!urlObject) ? window.location : urlObject;
  var params    = [];

  for (var key in paramsAssoc) {
    params.push(key+'='+paramsAssoc[key]);
  }

  params = (0 < params.length) ? '?'+params.join('&') : '';

  return urlObject.origin + urlObject.pathname + params;
};

function getUrlParamsAssoc (urlObject) {
  urlObject = (!urlObject) ? window.location : urlObject;

  if (!urlObject.search) { return {}; }

  var params      = urlObject.search.replace('?', '').split('&');
  var paramsAssoc = {};
  var split       = [];

  for (var i = params.length - 1; i >= 0; i--) {
    split = params[i].split('=');
    paramsAssoc[split[0]] = split[1];
  }

  return paramsAssoc;
};