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How can I get complex URI query string parameters in native JavaScript like in PHP?

My question is about full power solution for parsing ANY complex URI parameters using just normal browser's Javascript. Like it do PHP, for simple code compatibility between JS and PHP sources.
But the first, let us see some particular known decisions:
1.
There is popular question and answers on StackOverflow, see How can I get query string values in JavaScript?
You can find there quite simple solutions for common SIMPLE cases. For example, like handling this scalar parameters like this one:
https://example.com/?name=Jonathan&age=18
It has no answers for handling complex query params. (As far as I could see for answers with source codes and author comments)
2.
Also you may use an URL object in modern browsers, see https://developer.mozilla.org/en-US/docs/Web/API/URL, or exactly https://developer.mozilla.org/en-US/docs/Web/API/URL/searchParams
It is enought powerful and you don't need to write or load any code for parsing URI parameters - just use
var params = (new URL(document.location)).searchParams;
var name = params.get("name"); // is the string "Jonathan"
var age = parseInt(params.get("age")); // is the number 18
This approach has such disadvantage that URL is available only in most of modern browsers, - other browsers or outdated versions of browsers will fail.
So, what I need. I need parsing any complex URI params, like
https://example.com/?a=edit&u[name]=Jonathan&u[age]=18&area[]=1&area[]=20&u[own][]=car&u[own][]=bike&u[funname]=O%27Neel%20mc%20Fly&empty=&nulparam&the%20message=Hello%20World
to
{
'a': 'edit',
'u': {
'name': 'Jonathan',
'age': '18',
'own': ['car', 'bike'],
'funname': 'O\'Neel mc Fly'
},
'area': [1, 20],
'empty': '',
'nulparam': null,
'the message': 'Hello World'
}
Preferrable answer is just plain readable javascript source. Simple and small wide-used library can be accepted too, but this question is not about them.
`
PS:
To start I just publish my own current solution for parsing URI params and vice versa for making URI from params. Any comments for it are welcome.
Hope this helps to save time for lot of coders later.

My solution
Usage:
var params = getQueryParams(location.search);
var params = getQueryParams();
var params = {...};
var path = '...';
var url = path;
var urlSearch = getQueryString(params);
if (urlSearch) {
url += '?' + urlSearch;
}
history.replaceState({"autoUrl": url}, "autoreplace", url);
Code:
function getQueryParams(qs) {
if (typeof qs === 'undefined') {
qs = location.search;
}
qs = qs.replace(/\+/g, ' ');
var params = {},
tokens,
re = /[?&]?([^=]+)=([^&]*)/g;
while (tokens = re.exec(qs)) {
var name = decodeURIComponent(tokens[1]);
var value = decodeURIComponent(tokens[2]);
if (value.length == 0) {
continue;
}
if (name.substr(-2) == '[]') {
name = name.substr(0, name.length - 2);
if (typeof params[name] === 'undefined') {
params[name] = [];
}
if (value === '') {
continue;
}
params[name].push(value);
continue;
}
if (name.substr(-1) == ']') {
var nameParts = name.split('[');
name = nameParts[0];
for (var i = 1; i < nameParts.length; i++) {
nameParts[i] = nameParts[i].substr(0, nameParts[i].length - 1);
}
var ptr = params;
for (var i = 0; i < nameParts.length - 1; i++) {
name = nameParts[i];
if (typeof ptr[name] === 'undefined') {
ptr[name] = {};
}
ptr = ptr[name];
}
name = nameParts[nameParts.length - 1];
ptr[name] = value;
continue;
}
params[name] = value;
}
return params;
}
function getQueryString(params) {
var paramsStringParts = [];
for (var name in params) {
if (params[name] instanceof Array) {
paramsStringParts.push( name + '[]=' + params[name].join('&' + name + '[]=') );
} else if (typeof params[name] === 'object') {
var makeFlattern = function(obj){
var result = [];
if (obj instanceof Array) {
for (var i = 0; i < obj.length; i++) {
result.push('[]=' + obj[i]);
}
return result;
}
for (var i in obj) {
if (typeof obj[i] === 'object') {
var subResult = makeFlattern(obj[i]);
for (var j = 0; j < subResult.length; j++) {
result.push('[' + i + ']' + subResult[j]);
}
continue;
}
result.push('[' + i + ']=' + obj[i]);
}
return result;
};
paramsStringParts.push( name + makeFlattern(params[name]).join('&' + name) );
} else {
paramsStringParts.push( name + '=' + params[name] );
}
}
return paramsStringParts.join('&');
}

A bit late, but just struggled over the same problem, solution was very simple:
use encodeURIComponent(...) for the stringified complex objects, the result can then be used as normal queryString-Part.
In the result-side the query-string-parameters have to be un-stringified.
Example:
var complex_param_obj = {
value1: 'Wert1',
value2:4711
};
console.log(restored_param_obj);
var complex_param_str = encodeURIComponent(JSON.stringify(complex_param_obj));
console.log(complex_param_str);
var complex_param_url = 'http://test_page.html?complex_param=' + complex_param_str;
//on the result-side you would use something to extract the complex_param-attribute from the URL
//in this test-case:
var restored_param_obj = decodeURIComponent(complex_param_str);
console.log(restored_param_obj);

How to add or replace a query parameter in a URL using Javascript/jQuery?

I'm using jQuery 1.12. I want to replace a query string parameter in my window's URL query string, or add the parameter if doesn't exist. I tried the below:
new_url = window.location.href.replace( /[\?#].*|$/, "?order_by=" + data_val )
window.location.href = new_url
but what I'm discovering is that this wipes out all previous parameters in the query string, which I don't want. If the query string is:
?a=1&b=2
I would want the new query string to be:
?a=2&b=2&order_by=data
and if the query string was:
?a=2&b=3&order_by=old_data
it would become:
?a=2&b=3&order_by=data

You could use a jQuery plugin to do the all the heavy lifting for you. It will parse the query string, and also reconstruct the updated query string for you. Much less code to deal with.
Plugin Download Page
Github Repo
// URL: ?a=2&b=3&order_by=old_data
var order_by = $.query.get('order_by');
//=> old_data
// Conditionally modify parameter value
if (order_by) {
order_by = “data”;
}
// Inject modified parameter back into query string
var newUrl = $.query.set(“order_by”, order_by).toString();
//=> ?a=2&b=3&order_by=data
For those using Node.js, there is a package for this available in NPM.
NPM Package
Github Repo
var queryString = require('query-string');
var parsed = queryString.parse('?a=2&b=3&order_by=old_data'); // location.search
// Conditionally modify parameter value
if (parsed.order_by) {
parsed.order_by = 'data';
}
// Inject modified parameter back into query string
const newQueryString = queryString.stringify(parsed);
//=> a=2&b=3&order_by=data

A good solution ought to handle all of the following:
A URL that already has an order_by query parameter, optionally with whitespace before the equals sign. This can be further divided into cases where the order_by appears at the start, middle or end of the query string.
A URL that doesn't already have and order_by query parameter but does already have a question mark to delimit the query string.
A URL that doesn't already have and order_by query parameter and doesn't already have a question mark to delimit the query string.
The following will handle the cases above:
if (/[?&]order_by\s*=/.test(oldUrl)) {
newUrl = oldUrl.replace(/(?:([?&])order_by\s*=[^?&]*)/, "$1order_by=" + data_val);
} else if (/\?/.test(oldUrl)) {
newUrl = oldUrl + "&order_by=" + data_val;
} else {
newUrl = oldUrl + "?order_by=" + data_val;
}
as demonstrated below:
getNewUrl("?a=1&b=2");
getNewUrl("?a=2&b=3&order_by=old_data");
getNewUrl("?a=2&b=3&order_by = old_data&c=4");
getNewUrl("?order_by=old_data&a=2&b=3");
getNewUrl("http://www.stackoverflow.com");
function getNewUrl(oldUrl) {
var data_val = "new_data";
var newUrl;
if (/[?&]order_by\s*=/.test(oldUrl)) {
newUrl = oldUrl.replace(/(?:([?&])order_by\s*=[^?&]*)/, "$1order_by=" + data_val);
} else if (/\?/.test(oldUrl)) {
newUrl = oldUrl + "&order_by=" + data_val;
} else {
newUrl = oldUrl + "?order_by=" + data_val;
}
console.log(oldUrl + "\n...becomes...\n" + newUrl);
}

something like this?
let new_url = "";
if (window.location.search && window.location.search.indexOf('order_by=') != -1) {
new_url = window.location.search.replace( /order_by=\w*\d*/, "order_by=" + data_val);
} else if (window.location.search) {
new_url = window.location.search + "&order_by=" + data_val;
} else {
new_url = window.location.search + "?order_by=" + data_val;
}
window.location.href = new_url;

function addOrReplaceOrderBy(newData) {
var stringToAdd = "order_by=" + newData;
if (window.location.search == "")
return window.location.href + stringToAdd;
if (window.location.search.indexOf('order_by=') == -1)
return window.location.href + stringToAdd;
var newSearchString = "";
var searchParams = window.location.search.substring(1).split("&");
for (var i = 0; i < searchParams.length; i++) {
if (searchParams[i].indexOf('order_by=') > -1) {
searchParams[i] = "order_by=" + newData;
break;
}
}
return window.location.href.split("?")[0] + "?" + searchParams.join("&");
}
window.location.href = addOrReplaceOrderBy("new_order_by");
A little long but I think it works as intended.

You can remove parameter from query string using URLSearchParams https://developer.mozilla.org/ru/docs/Web/API/URLSearchParams?param11=val
It is not yet supported by IE and Safari, but you can use it by adding polyfill https://github.com/jerrybendy/url-search-params-polyfill
And for accessing or modifying query part of the URI you should use "search" property of the window.location.
Working code example:
var a = document.createElement("a")
a.href = "http://localhost.com?param1=val&param2=val2&param3=val3#myHashCode";
var queryParams = new URLSearchParams(a.search)
queryParams.delete("param2")
a.search = queryParams.toString();
console.log(a.href);

Try this:
For reading parameters:
const data = ['example.com?var1=value1&var2=value2&var3=value3', 'example.com?a=2&b=2&order_by=data']
const getParameters = url => {
const parameters = url.split('?')[1],
regex = /(\w+)=(\w+)/g,
obj = {}
let temp
while (temp = regex.exec(parameters)){
obj[temp[1]] = decodeURIComponent(temp[2])
}
return obj
}
for(let url of data){
console.log(getParameters(url))
}
For placing only this parameters:
const data = ['example.com?zzz=asd']
const parameters = {a:1, b:2, add: "abs"}
const setParameters = (url, parameters) => {
const keys = Object.keys(parameters)
let temp = url.split('?')[0] += '?'
for (let i = 0; i < keys.length; i++) {
temp += `${keys[i]}=${parameters[keys[i]]}${i == keys.length - 1 ? '' : '&'}`
}
return temp
}
for (let url of data){
console.log(setParameters(url, parameters))
}
And finaly for inserting (or replace while exists)
const data = ['example.com?a=123&b=3&sum=126']
const parameters = {order_by: 'abc', a: 11}
const insertParameters = (url, parameters) => {
const keys = Object.keys(parameters)
let result = url
for (let i = 0; i < keys.length; i++){
if (result.indexOf(keys[i]) === -1) {
result += `&${keys[i]}=${encodeURIComponent(parameters[keys[i]])}`
} else {
let regex = new RegExp(`${keys[i]}=(\\w+)`)
result = result.replace(regex, `&${keys[i]}=${encodeURIComponent(parameters[keys[i]])}`)
}
}
return result
}
for (let url of data){
console.log(insertParameters(url, parameters))
}
Hope this works for you ;)
After using function just replace window.location.href

This small function could help.
function changeSearchQueryParameter(oldParameter,newParameter,newValue) {
var parameters = location.search.replace("?", "").split("&").filter(function(el){ return el !== "" });
var out = "";
var count = 0;
if(oldParameter.length>0) {
if(newParameter.length>0 && (newValue.length>0 || newValue>=0)){
out += "?";
var params = [];
parameters.forEach(function(v){
var vA = v.split("=");
if(vA[0]==oldParameter) {
vA[0]=newParameter;
if((newValue.length>0 || newValue>=0)) {
vA[1] = newValue;
}
} else {
count++;
}
params.push(vA.join("="));
});
if(count==parameters.length) {
params.push([newParameter,newValue].join("="));
}
params = params.filter(function(el){ return el !== "" });
if(params.length>1) {
out += params.join("&");
}
if(params.length==1) {
out += params[0];
}
}
} else {
if((newParameter.length>0) && (newValue.length>0 || newValue>=0)){
if(location.href.indexOf("?")!==-1) {
var out = "&"+newParameter+"="+newValue;
} else {
var out = "?"+newParameter+"="+newValue;
}
}
}
return location.href+out;
}
// if old query parameter is declared but does not exist in url then new parameter and value is simply added if it exists it will be replaced
console.log(changeSearchQueryParameter("ib","idx",5));
// add new parameter and value in url
console.log(changeSearchQueryParameter("","idy",5));
// if no new or old parameter are present url does not change
console.log(changeSearchQueryParameter("","",5));
console.log(changeSearchQueryParameter("","",""));

Maybe you could try tweaking the regular expression to retrieve only the values you're looking for, then add or update them in a helper function, something like this:
function paramUpdate(param) {
var url = window.location.href,
regExp = new RegExp(param.key + '=([a-z0-9\-\_]+)(?:&)?'),
existsMatch = url.match(regExp);
if (!existsMatch) {
return url + '&' + param.key + '=' + param.value
}
var paramToUpdate = existsMatch[0],
valueToReplace = existsMatch[1],
updatedParam = paramToUpdate.replace(valueToReplace, param.value);
return url.replace(paramToUpdate, updatedParam);
}
var new_url = paramUpdate({
key: 'order_by',
value: 'id'
});
window.location.href = new_url;
Hope it works well for your needs!

To use Regex pattern, I prefer this one:
var oldUrl = "http://stackoverflow.com/";
var data_val = "newORDER" ;
var r = /^(.+order_by=).+?(&|$)(.*)$/i ;
var newUrl = "";
var matches = oldUrl.match(r) ;
if(matches===null){
newUrl = oldUrl + ((oldUrl.indexOf("?")>-1)?"&":"?") + "order_by=" + data_val ;
}else{
newUrl = matches[1]+data_val+matches[2]+matches[3] ;
}
conole.log(newUrl);
If no order_by exist, matches is null and order_by=.. should come after ? or & (if other parameters exist, new one needs &).
If order_by exist, matches has 3 items, see here

Based on AVAVT´s answer I improved it so it takes any key, and I also fixed the missing "?" if there was no querystring
function addOrReplace(key, value) {
var stringToAdd = key+"=" + value;
if (window.location.search == "")
return window.location.href + '?'+stringToAdd;
if (window.location.search.indexOf(key+'=') == -1)
return window.location.href + stringToAdd;
var newSearchString = "";
var searchParams = window.location.search.substring(1).split("&");
for (var i = 0; i < searchParams.length; i++) {
if (searchParams[i].indexOf(key+'=') > -1) {
searchParams[i] = key+"=" + value;
break;
}
}
return window.location.href.split("?")[0] + "?" + searchParams.join("&");
}
usuage:
window.location.href = addOrReplace('order_by', 'date_created');
if you would not want to reload the page you can use pushState Api
if (history.pushState) {
var newurl = addOrReplace('order_by', 'date_created');
window.history.pushState({path:newurl},'',newurl);
}

function myFunction() {
var str = "https://www.citicards.com/cards/credit/application/flow.action?app=UNSOL&HKOP=828cca70910b4fe25e118bd0b59b89c3c7c560df877909495d8252d20026cf8d&cmp=afa|acquire|2003|comparecards&ranMID=44660&ranEAID=2759285&ProspectID=516511657A844EF3A6F0C2B1E85FEFB0&ID=3000";
var res = str.split("&");
var myKey;
if (!str.includes("ranSiteID")) {
console.log("key not found ");
res.push('ranSiteID=samplearsdyfguh.090-nuvbknlmc0.gvyhbjknl')
console.log(res.join("&"));
} else {
res.map(function(key) {
console.log("my keys", key);
if (key.includes("ranSiteID")) {
console.log("my required-->key", key);
mykey = key.split("=");
console.log(mykey);
}
})
}
document.getElementById("demo").innerHTML = res;
}
<!DOCTYPE html>
<html>
<body>
<p>Click the button to display the array values after the split.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
</body>
</html>

tracking utm campaign params with mixpanel as people properties

Here's my little javascript, which will save utm params into people properties. Really useful for filtering, which user was acquired by a specific marketing channel.

Just put this code after you initialize mixpanel:
<script type="text/javascript">
function getQueryStrings() {
var assoc = {};
var decode = function (s) { return decodeURIComponent(s.replace(/\+/g, " ")); };
var queryString = location.search.substring(1);
var keyValues = queryString.split('&');
for(var i in keyValues) {
var key = keyValues[i].split('=');
if (key.length > 1) {
assoc[decode(key[0])] = decode(key[1]);
}
}
return assoc;
}
var params = getQueryStrings();
for(var i in params) {
var match = /utm_[a-z]+/
if (match.test(i)) {
var value = params[i];
mixpanel.people.set_once(i, value);
}
}
</script>

Getting data from url hash in javascript

I am trying to read the "source" parameter and the "group" parameter from the url hash below. I have no idea how to use regex and keep ending up with blank variables.
How do I read "source" and "group" parameters from the url hash below
console.log(urlObj.hash); // #source-items?source=1002&?group=Menu
var source = urlObj.hash.replace( /.*source=/, "");

If you remove the ? after & and you can use something like this:
function parseParams() {
var params = window.location.hash.split('?')[1].split('&').map(function(item) {
return item.split('=');
});
var namedparams = {};
for (i=-1; param = params[++i]; ) {
namedparams[param[0]] = param[1];
}
return namedparams;
}
This is how you use this function:
var params = parseParams();
params.group; // the group parameter
params.source; // the source parameter

Try
function getParameterByName(urlString, name)
{
name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
var regexS = "[\\?&]" + name + "=([^&#]*)";
var regex = new RegExp(regexS);
var results = regex.exec(urlString);
if(results == null)
return "";
else
return decodeURIComponent(results[1].replace(/\+/g, " "));
}
And invoke this by getParameterByName(urlObj.hash, "source");
Update : This is slightly modified version of the answer to Get query string values in JavaScript

Change URL parameters and specify defaults using JavaScript

I have this URL:
site.fwx?position=1&archiveid=5000&columns=5&rows=20&sorting=ModifiedTimeAsc
what I need is to be able to change the 'rows' url param value to something i specify, lets say 10. And if the 'rows' doesn't exist, I need to add it to the end of the url and add the value i've already specified (10).

I've extended Sujoy's code to make up a function.
/**
* http://stackoverflow.com/a/10997390/11236
*/
function updateURLParameter(url, param, paramVal){
var newAdditionalURL = "";
var tempArray = url.split("?");
var baseURL = tempArray[0];
var additionalURL = tempArray[1];
var temp = "";
if (additionalURL) {
tempArray = additionalURL.split("&");
for (var i=0; i<tempArray.length; i++){
if(tempArray[i].split('=')[0] != param){
newAdditionalURL += temp + tempArray[i];
temp = "&";
}
}
}
var rows_txt = temp + "" + param + "=" + paramVal;
return baseURL + "?" + newAdditionalURL + rows_txt;
}
Function Calls:
var newURL = updateURLParameter(window.location.href, 'locId', 'newLoc');
newURL = updateURLParameter(newURL, 'resId', 'newResId');
window.history.replaceState('', '', updateURLParameter(window.location.href, "param", "value"));
Updated version that also take care of the anchors on the URL.
function updateURLParameter(url, param, paramVal)
{
var TheAnchor = null;
var newAdditionalURL = "";
var tempArray = url.split("?");
var baseURL = tempArray[0];
var additionalURL = tempArray[1];
var temp = "";
if (additionalURL)
{
var tmpAnchor = additionalURL.split("#");
var TheParams = tmpAnchor[0];
TheAnchor = tmpAnchor[1];
if(TheAnchor)
additionalURL = TheParams;
tempArray = additionalURL.split("&");
for (var i=0; i<tempArray.length; i++)
{
if(tempArray[i].split('=')[0] != param)
{
newAdditionalURL += temp + tempArray[i];
temp = "&";
}
}
}
else
{
var tmpAnchor = baseURL.split("#");
var TheParams = tmpAnchor[0];
TheAnchor = tmpAnchor[1];
if(TheParams)
baseURL = TheParams;
}
if(TheAnchor)
paramVal += "#" + TheAnchor;
var rows_txt = temp + "" + param + "=" + paramVal;
return baseURL + "?" + newAdditionalURL + rows_txt;
}

I think you want the query plugin.
E.g.:
window.location.search = jQuery.query.set("rows", 10);
This will work regardless of the current state of rows.

Quick little solution in pure js, no plugins needed:
function replaceQueryParam(param, newval, search) {
var regex = new RegExp("([?;&])" + param + "[^&;]*[;&]?");
var query = search.replace(regex, "$1").replace(/&$/, '');
return (query.length > 2 ? query + "&" : "?") + (newval ? param + "=" + newval : '');
}
Call it like this:
window.location = '/mypage' + replaceQueryParam('rows', 55, window.location.search)
Or, if you want to stay on the same page and replace multiple params:
var str = window.location.search
str = replaceQueryParam('rows', 55, str)
str = replaceQueryParam('cols', 'no', str)
window.location = window.location.pathname + str
edit, thanks Luke: To remove the parameter entirely, pass false or null for the value: replaceQueryParam('rows', false, params). Since 0 is also falsy, specify '0'.

To answer my own question 4 years later, after having learned a lot. Especially that you shouldn't use jQuery for everything. I've created a simple module that can parse/stringify a query string. This makes it easy to modify the query string.
You can use query-string as follows:
// parse the query string into an object
var q = queryString.parse(location.search);
// set the `row` property
q.rows = 10;
// convert the object to a query string
// and overwrite the existing query string
location.search = queryString.stringify(q);

A modern approach to this is to use native standard based URLSearchParams. It's supported by all major browsers, except for IE where they're polyfills available
const paramsString = "site.fwx?position=1&archiveid=5000&columns=5&rows=20&sorting=ModifiedTimeAsc"
const searchParams = new URLSearchParams(paramsString);
searchParams.set('rows', 10);
console.log(searchParams.toString()); // return modified string.

Ben Alman has a good jquery querystring/url plugin here that allows you to manipulate the querystring easily.
As requested -
Goto his test page here
In firebug enter the following into the console
jQuery.param.querystring(window.location.href, 'a=3&newValue=100');
It will return you the following amended url string
http://benalman.com/code/test/js-jquery-url-querystring.html?a=3&b=Y&c=Z&newValue=100#n=1&o=2&p=3
Notice the a querystring value for a has changed from X to 3 and it has added the new value.
You can then use the new url string however you wish e.g
using document.location = newUrl or change an anchor link etc

This is the modern way to change URL parameters:
function setGetParam(key,value) {
if (history.pushState) {
var params = new URLSearchParams(window.location.search);
params.set(key, value);
var newUrl = window.location.origin
+ window.location.pathname
+ '?' + params.toString();
window.history.pushState({path:newUrl},'',newUrl);
}
}

you can do it via normal JS also
var url = document.URL
var newAdditionalURL = "";
var tempArray = url.split("?");
var baseURL = tempArray[0];
var aditionalURL = tempArray[1];
var temp = "";
if(aditionalURL)
{
var tempArray = aditionalURL.split("&");
for ( var i in tempArray ){
if(tempArray[i].indexOf("rows") == -1){
newAdditionalURL += temp+tempArray[i];
temp = "&";
}
}
}
var rows_txt = temp+"rows=10";
var finalURL = baseURL+"?"+newAdditionalURL+rows_txt;

Use URLSearchParams to check, get and set the parameters value into URL
Here is the example to get the current URL and set new parameter and update the URL or reload the page as per your needs
var rows = 5; // value that you want to set
var url = new URL(window.location);
(url.searchParams.has('rows') ? url.searchParams.set('rows', rows) : url.searchParams.append('rows', rows));
url.search = url.searchParams;
url = url.toString();
// if you want to append into URL without reloading the page
history.pushState({}, null, url);
// want to reload the window with a new param
window.location = url;

2020 Solution: sets the variable or removes iti if you pass null or undefined to the value.
var setSearchParam = function(key, value) {
if (!window.history.pushState) {
return;
}
if (!key) {
return;
}
var url = new URL(window.location.href);
var params = new window.URLSearchParams(window.location.search);
if (value === undefined || value === null) {
params.delete(key);
} else {
params.set(key, value);
}
url.search = params;
url = url.toString();
window.history.replaceState({url: url}, null, url);
}

Would a viable alternative to String manipulation be to set up an html form and just modify the value of the rows element?
So, with html that is something like
<form id='myForm' target='site.fwx'>
<input type='hidden' name='position' value='1'/>
<input type='hidden' name='archiveid' value='5000'/>
<input type='hidden' name='columns' value='5'/>
<input type='hidden' name='rows' value='20'/>
<input type='hidden' name='sorting' value='ModifiedTimeAsc'/>
</form>
With the following JavaScript to submit the form
var myForm = document.getElementById('myForm');
myForm.rows.value = yourNewValue;
myForm.submit();
Probably not suitable for all situations, but might be nicer than parsing the URL string.

URL query parameters can be easily modified using URLSearchParams and History interfaces:
// Construct URLSearchParams object instance from current URL querystring.
var queryParams = new URLSearchParams(window.location.search);
// Set new or modify existing parameter value.
//queryParams.set("myParam", "myValue");
queryParams.set("rows", "10");
// Replace current querystring with the new one.
history.replaceState(null, null, "?"+queryParams.toString());
Alternatively instead of modifying current history entry using replaceState() we can use pushState() method to create a new one:
history.pushState(null, null, "?"+queryParams.toString());
https://zgadzaj.com/development/javascript/how-to-change-url-query-parameter-with-javascript-only

You can use this my library to do the job: https://github.com/Mikhus/jsurl
var url = new Url('site.fwx?position=1&archiveid=5000&columns=5&rows=20&sorting=ModifiedTimeAsc');
url.query.rows = 10;
alert( url);

Consider this one:
const myUrl = new URL("http://www.example.com?columns=5&rows=20");
myUrl.searchParams.set('rows', 10);
console.log(myUrl.href); // http://www.example.com?columns=5&rows=10
myUrl.searchParams.set('foo', 'bar'); // add new param
console.log(myUrl.href); // http://www.example.com?columns=5&rows=10&foo=bar
It will do exactly the same thing you required. Please note URL must have correct format. In your example you have to specify protocol (either http or https)

I wrote a little helper function that works with any select. All you need to do is add the class "redirectOnChange" to any select element, and this will cause the page to reload with a new/changed querystring parameter, equal to the id and value of the select, e.g:
<select id="myValue" class="redirectOnChange">
<option value="222">test222</option>
<option value="333">test333</option>
</select>
The above example would add "?myValue=222" or "?myValue=333" (or using "&" if other params exist), and reload the page.
jQuery:
$(document).ready(function () {
//Redirect on Change
$(".redirectOnChange").change(function () {
var href = window.location.href.substring(0, window.location.href.indexOf('?'));
var qs = window.location.href.substring(window.location.href.indexOf('?') + 1, window.location.href.length);
var newParam = $(this).attr("id") + '=' + $(this).val();
if (qs.indexOf($(this).attr("id") + '=') == -1) {
if (qs == '') {
qs = '?'
}
else {
qs = qs + '&'
}
qs = qs + newParam;
}
else {
var start = qs.indexOf($(this).attr("id") + "=");
var end = qs.indexOf("&", start);
if (end == -1) {
end = qs.length;
}
var curParam = qs.substring(start, end);
qs = qs.replace(curParam, newParam);
}
window.location.replace(href + '?' + qs);
});
});

Using javascript URL:
var url = new URL(window.location);
(url.searchParams.has('rows') ? url.searchParams.set('rows', rows) : url.searchParams.append('rows', rows));
window.location = url;

var url = new URL(window.location.href);
var search_params = url.searchParams;
search_params.set("param", value);
url.search = search_params.toString();
var new_url = url.pathname + url.search;
window.history.replaceState({}, '', new_url);

Here I have taken Adil Malik's answer and fixed the 3 issues I identified with it.
/**
* Adds or updates a URL parameter.
*
* #param {string} url the URL to modify
* #param {string} param the name of the parameter
* #param {string} paramVal the new value for the parameter
* #return {string} the updated URL
*/
self.setParameter = function (url, param, paramVal){
// http://stackoverflow.com/a/10997390/2391566
var parts = url.split('?');
var baseUrl = parts[0];
var oldQueryString = parts[1];
var newParameters = [];
if (oldQueryString) {
var oldParameters = oldQueryString.split('&');
for (var i = 0; i < oldParameters.length; i++) {
if(oldParameters[i].split('=')[0] != param) {
newParameters.push(oldParameters[i]);
}
}
}
if (paramVal !== '' && paramVal !== null && typeof paramVal !== 'undefined') {
newParameters.push(param + '=' + encodeURI(paramVal));
}
if (newParameters.length > 0) {
return baseUrl + '?' + newParameters.join('&');
} else {
return baseUrl;
}
}

In the URLSearchParams documentation, there's a very clean way of doing this, without affecting the history stack.
// URL: https://example.com?version=1.0
const params = new URLSearchParams(location.search);
params.set('version', 2.0);
window.history.replaceState({}, '', `${location.pathname}?${params}`);
// URL: https://example.com?version=2.0
Similarily, to remove a parameter
params.delete('version')
window.history.replaceState({}, '', `${location.pathname}?${params}`);
// URL: https://example.com?

let url= new URL("https://example.com/site.fwx?position=1&archiveid=5000&columns=5&rows=20&sorting=ModifiedTimeAsc")
url.searchParams.set('rows', 10)
console.log(url.toString())

Here is what I do. Using my editParams() function, you can add, remove, or change any parameter, then use the built in replaceState() function to update the URL:
window.history.replaceState('object or string', 'Title', 'page.html' + editParams('sorting', ModifiedTimeAsc));
// background functions below:
// add/change/remove URL parameter
// use a value of false to remove parameter
// returns a url-style string
function editParams (key, value) {
key = encodeURI(key);
var params = getSearchParameters();
if (Object.keys(params).length === 0) {
if (value !== false)
return '?' + key + '=' + encodeURI(value);
else
return '';
}
if (value !== false)
params[key] = encodeURI(value);
else
delete params[key];
if (Object.keys(params).length === 0)
return '';
return '?' + $.map(params, function (value, key) {
return key + '=' + value;
}).join('&');
}
// Get object/associative array of URL parameters
function getSearchParameters () {
var prmstr = window.location.search.substr(1);
return prmstr !== null && prmstr !== "" ? transformToAssocArray(prmstr) : {};
}
// convert parameters from url-style string to associative array
function transformToAssocArray (prmstr) {
var params = {},
prmarr = prmstr.split("&");
for (var i = 0; i < prmarr.length; i++) {
var tmparr = prmarr[i].split("=");
params[tmparr[0]] = tmparr[1];
}
return params;
}

My solution:
const setParams = (data) => {
if (typeof data !== 'undefined' && typeof data !== 'object') {
return
}
let url = new URL(window.location.href)
const params = new URLSearchParams(url.search)
for (const key of Object.keys(data)) {
if (data[key] == 0) {
params.delete(key)
} else {
params.set(key, data[key])
}
}
url.search = params
url = url.toString()
window.history.replaceState({ url: url }, null, url)
}
Then just call "setParams" and pass an object with data you want to set.
Example:
$('select').on('change', e => {
const $this = $(e.currentTarget)
setParams({ $this.attr('name'): $this.val() })
})
In my case I had to update a html select input when it changes and if the value is "0", remove the parameter. You can edit the function and remove the parameter from the url if the object key is "null" as well.
Hope this helps yall

If you want to change the url in address bar:
const search = new URLSearchParams(location.search);
search.set('rows', 10);
location.search = search.toString();
Note, changing location.search reloads the page.

Here is a simple solution using the query-string library.
const qs = require('query-string')
function addQuery(key, value) {
const q = qs.parse(location.search)
const url = qs.stringifyUrl(
{
url: location.pathname,
query: {
...q,
[key]: value,
},
},
{ skipEmptyString: true }
);
window.location.href = url
// if you are using Turbolinks
// add this: Turbolinks.visit(url)
}
// Usage
addQuery('page', 2)
If you are using react without react-router
export function useAddQuery() {
const location = window.location;
const addQuery = useCallback(
(key, value) => {
const q = qs.parse(location.search);
const url = qs.stringifyUrl(
{
url: location.pathname,
query: {
...q,
[key]: value,
},
},
{ skipEmptyString: true }
);
window.location.href = url
},
[location]
);
return { addQuery };
}
// Usage
const { addQuery } = useAddQuery()
addQuery('page', 2)
If you are using react with react-router
export function useAddQuery() {
const location = useLocation();
const history = useHistory();
const addQuery = useCallback(
(key, value) => {
let pathname = location.pathname;
let searchParams = new URLSearchParams(location.search);
searchParams.set(key, value);
history.push({
pathname: pathname,
search: searchParams.toString()
});
},
[location, history]
);
return { addQuery };
}
// Usage
const { addQuery } = useAddQuery()
addQuery('page', 2)
PS: qs is the import from query-string module.

Another variation on Sujoy's answer. Just changed the variable names & added a namespace wrapper:
window.MyNamespace = window.MyNamespace || {};
window.MyNamespace.Uri = window.MyNamespace.Uri || {};
(function (ns) {
ns.SetQueryStringParameter = function(url, parameterName, parameterValue) {
var otherQueryStringParameters = "";
var urlParts = url.split("?");
var baseUrl = urlParts[0];
var queryString = urlParts[1];
var itemSeparator = "";
if (queryString) {
var queryStringParts = queryString.split("&");
for (var i = 0; i < queryStringParts.length; i++){
if(queryStringParts[i].split('=')[0] != parameterName){
otherQueryStringParameters += itemSeparator + queryStringParts[i];
itemSeparator = "&";
}
}
}
var newQueryStringParameter = itemSeparator + parameterName + "=" + parameterValue;
return baseUrl + "?" + otherQueryStringParameters + newQueryStringParameter;
};
})(window.MyNamespace.Uri);
Useage is now:
var changedUrl = MyNamespace.Uri.SetQueryStringParameter(originalUrl, "CarType", "Ford");

I too have written a library for getting and setting URL query parameters in JavaScript.
Here is an example of its usage.
var url = Qurl.create()
, query
, foo
;
Get query params as an object, by key, or add/change/remove.
// returns { foo: 'bar', baz: 'qux' } for ?foo=bar&baz=qux
query = url.query();
// get the current value of foo
foo = url.query('foo');
// set ?foo=bar&baz=qux
url.query('foo', 'bar');
url.query('baz', 'qux');
// unset foo, leaving ?baz=qux
url.query('foo', false); // unsets foo

I was looking for the same thing and found: https://github.com/medialize/URI.js which is quite nice :)
-- Update
I found a better package: https://www.npmjs.org/package/qs it also deals with arrays in get params.

No library, using URL() WebAPI (https://developer.mozilla.org/en-US/docs/Web/API/URL)
function setURLParameter(url, parameter, value) {
let url = new URL(url);
if (url.searchParams.get(parameter) === value) {
return url;
}
url.searchParams.set(parameter, value);
return url.href;
}
This doesn't work on IE: https://developer.mozilla.org/en-US/docs/Web/API/URL#Browser_compatibility

I know this is an old question. I have enhanced the function above to add or update query params. Still a pure JS solution only.
function addOrUpdateQueryParam(param, newval, search) {
var questionIndex = search.indexOf('?');
if (questionIndex < 0) {
search = search + '?';
search = search + param + '=' + newval;
return search;
}
var regex = new RegExp("([?;&])" + param + "[^&;]*[;&]?");
var query = search.replace(regex, "$1").replace(/&$/, '');
var indexOfEquals = query.indexOf('=');
return (indexOfEquals >= 0 ? query + '&' : query + '') + (newval ? param + '=' + newval : '');
}

my function support removing param
function updateURLParameter(url, param, paramVal, remove = false) {
var newAdditionalURL = '';
var tempArray = url.split('?');
var baseURL = tempArray[0];
var additionalURL = tempArray[1];
var rows_txt = '';
if (additionalURL)
newAdditionalURL = decodeURI(additionalURL) + '&';
if (remove)
newAdditionalURL = newAdditionalURL.replace(param + '=' + paramVal, '');
else
rows_txt = param + '=' + paramVal;
window.history.replaceState('', '', (baseURL + "?" + newAdditionalURL + rows_txt).replace('?&', '?').replace('&&', '&').replace(/\&$/, ''));
}