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Getting URL parameters and filter out a specific parameter

I want to filter out a specific parameter out of the URL. I have the following situation:
The page got loaded (for example: http://test.com/default.aspx?folder=app&test=true)
When the page is loaded a function is called to push a entry to the history (pushState): ( for example: http://test.com/default.aspx?folder=app&test=true&state=1)
Now I want to call a function that reads all the parameters and output all these parameters expect for the state. So that I end up with: "?folder=app&test=true" (just a string value, no array or object). Please keep in mind that I do not know what all the names of the parameters are execpt for the state parameter
What I have tried
I know I can get all the parameters by using the following code:
window.location.search
But it will result in:
?folder=app&test=true&state=1
I try to split the url, for example:
var url = '?folder=app&test=true&state=1';
url = url.split('&state=');
console.log(url);
But that does not work. Also because the state number is dynamic in each request. A solution might be remove the last parameter out of the url but I also do not know if that ever will be the case therefore I need some filtering mechanisme that will only filter out the
state=/*regex for a number*/

To achieve this you can convert the querystring provided to the page to an object, remove the state property of the result - assuming it exists - then you can convert the object back to a querystring ready to use in pushState(). Something like this:
var qsToObj = function(qs) {
qs = qs.substring(1);
if (!qs) return {};
return qs.split("&").reduce(function(prev, curr, i, arr) {
var p = curr.split("=");
prev[decodeURIComponent(p[0])] = decodeURIComponent(p[1]);
return prev;
}, {});
}
var qs = '?'; // window.location.search;
var obj = qsToObj(qs);
delete obj.state;
console.log(obj);
var newQs = $.param(obj);
console.log(newQs);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Credit to this answer for the querystring to object logic.

I would agree with Rory's answer, you should have an object to safely manipulate params. This is the function that I use.
function urlParamsObj(source) {
/* function returns an object with url parameters
URL sample: www.test.com?var1=value1&var2=value2
USE: var params = URLparamsObj();
alert(params.var2) --> output: value2
You can use it for a url-like string also: urlParamsObj("www.ok.uk?a=2&b=3")*/
var urlStr = source ? source : window.location.search ? window.location.search : ""
if (urlStr.indexOf("?") > -1) { // if there are params in URL
var param_array = urlStr.substring(urlStr.indexOf("?") + 1).split('&'),
theLength = param_array.length,
params = {},
i = 0,
x;
for (; i < theLength; i++) {
x = param_array[i].toString().split('=');
params[x[0]] = x[1];
}
return params;
}
return {};
}

A much simpler way to do this would be:
let url = new URL(window.location.href)
url.searchParams.delete('state');
window.location.search = url.search;
You can read about URLSearchParams.delete() in the MDN Web Docs.

Sorry if this is wrong just as i think &state=1,2,3,4,5,6 is absolute its just depends on number to pick states just like my web
var url = '?folder=app&test=true&state=1';
url = url.substring(0, url.indexOf('&s'));
$('#demo').text(url);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<span id='demo'></span>

var url = '?folder=app&test=true&state=1';
url = url.split('&folder=');
console.log(url);

Get Facebook referal in Chrome extension [duplicate]

This question already has answers here:
How can I get query string values in JavaScript?
(73 answers)
Closed 1 year ago.
I have a URL with some GET parameters as follows:
www.test.com/t.html?a=1&b=3&c=m2-m3-m4-m5
I need to get the whole value of c. I tried to read the URL, but I got only m2. How do I do this using JavaScript?

JavaScript itself has nothing built in for handling query string parameters.
Code running in a (modern) browser can use the URL object (a Web API). URL is also implemented by Node.js:
// You can get url_string from window.location.href if you want to work with
// the URL of the current page
var url_string = "http://www.example.com/t.html?a=1&b=3&c=m2-m3-m4-m5";
var url = new URL(url_string);
var c = url.searchParams.get("c");
console.log(c);
For older browsers (including Internet Explorer), you can use this polyfill.
You could also use one for URLSearchParams and extract the query string to pass to it with window.location.search.substring(1).
You could also use the code from the original version of this answer that predates URL. The above polyfill is robust and well tested and I strongly recommend it over this though.
You could access location.search, which would give you from the ? character on to the end of the URL or the start of the fragment identifier (#foo), whichever comes first.
Then you can parse it with this:
function parse_query_string(query) {
var vars = query.split("&");
var query_string = {};
for (var i = 0; i < vars.length; i++) {
var pair = vars[i].split("=");
var key = decodeURIComponent(pair.shift());
var value = decodeURIComponent(pair.join("="));
// If first entry with this name
if (typeof query_string[key] === "undefined") {
query_string[key] = value;
// If second entry with this name
} else if (typeof query_string[key] === "string") {
var arr = [query_string[key], value];
query_string[key] = arr;
// If third or later entry with this name
} else {
query_string[key].push(value);
}
}
return query_string;
}
var query_string = "a=1&b=3&c=m2-m3-m4-m5";
var parsed_qs = parse_query_string(query_string);
console.log(parsed_qs.c);
You can get the query string from the URL of the current page with:
var query = window.location.search.substring(1);
var qs = parse_query_string(query);

Most implementations I've seen miss out URL-decoding the names and the values.
Here's a general utility function that also does proper URL-decoding:
function getQueryParams(qs) {
qs = qs.split('+').join(' ');
var params = {},
tokens,
re = /[?&]?([^=]+)=([^&]*)/g;
while (tokens = re.exec(qs)) {
params[decodeURIComponent(tokens[1])] = decodeURIComponent(tokens[2]);
}
return params;
}
//var query = getQueryParams(document.location.search);
//alert(query.foo);

source
function gup( name, url ) {
if (!url) url = location.href;
name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
var regexS = "[\\?&]"+name+"=([^&#]*)";
var regex = new RegExp( regexS );
var results = regex.exec( url );
return results == null ? null : results[1];
}
gup('q', 'hxxp://example.com/?q=abc')

This is an easy way to check just one parameter:
Example URL:
http://myserver/action?myParam=2
Example Javascript:
var myParam = location.search.split('myParam=')[1]
if "myParam" exists in the URL... variable myParam will contain "2", otherwise it will be undefined.
Maybe you want a default value, in that case:
var myParam = location.search.split('myParam=')[1] ? location.search.split('myParam=')[1] : 'myDefaultValue';
Update: This works better:
var url = "http://www.example.com/index.php?myParam=384&login=admin"; // or window.location.href for current url
var captured = /myParam=([^&]+)/.exec(url)[1]; // Value is in [1] ('384' in our case)
var result = captured ? captured : 'myDefaultValue';
And it works right even when URL is full of parameters.

Browsers vendors have implemented a native way to do this via URL and URLSearchParams.
let url = new URL('http://www.test.com/t.html?a=1&b=3&c=m2-m3-m4-m5');
let searchParams = new URLSearchParams(url.search);
console.log(searchParams.get('c')); // outputs "m2-m3-m4-m5"
Currently supported in Firefox, Opera, Safari, Chrome and Edge. For a list of browser support see here.
https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams
https://developer.mozilla.org/en-US/docs/Web/API/URL/URL
https://url.spec.whatwg.org/
Eric Bidelman, an engineer at Google, recommends using this polyfill for unsupported browsers.

I found this ages ago, very easy:
function getUrlVars() {
var vars = {};
var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi,
function(m,key,value) {
vars[key] = value;
});
return vars;
}
Then call it like this:
var fType = getUrlVars()["type"];

You can get the query string in location.search, then you can split everything after the question mark:
var params = {};
if (location.search) {
var parts = location.search.substring(1).split('&');
for (var i = 0; i < parts.length; i++) {
var nv = parts[i].split('=');
if (!nv[0]) continue;
params[nv[0]] = nv[1] || true;
}
}
// Now you can get the parameters you want like so:
var abc = params.abc;

A super simple way using URLSearchParams.
function getParam(param){
return new URLSearchParams(window.location.search).get(param);
}
It's currently supported in Chrome, Firefox, Safari, Edge, and others.

I wrote a more simple and elegant solution.
var arr = document.URL.match(/room=([0-9]+)/)
var room = arr[1];

Here is a recursive solution that has no regex, and has minimal mutation (only the params object is mutated, which I believe is unavoidable in JS).
It's awesome because it:
Is recursive
Handles multiple parameters of the same name
Deals well with malformed parameter strings (missing values, so on)
Doesn't break if '=' is in the value
Performs URL decoding
And lastly, It's awesome because it...argh!!!
Code:
var get_params = function(search_string) {
var parse = function(params, pairs) {
var pair = pairs[0];
var parts = pair.split('=');
var key = decodeURIComponent(parts[0]);
var value = decodeURIComponent(parts.slice(1).join('='));
// Handle multiple parameters of the same name
if (typeof params[key] === "undefined") {
params[key] = value;
} else {
params[key] = [].concat(params[key], value);
}
return pairs.length == 1 ? params : parse(params, pairs.slice(1))
}
// Get rid of leading ?
return search_string.length == 0 ? {} : parse({}, search_string.substr(1).split('&'));
}
var params = get_params(location.search);
// Finally, to get the param you want
params['c'];

I made a function that does this:
var getUrlParams = function (url) {
var params = {};
(url + '?').split('?')[1].split('&').forEach(function (pair) {
pair = (pair + '=').split('=').map(decodeURIComponent);
if (pair[0].length) {
params[pair[0]] = pair[1];
}
});
return params;
};
Update 5/26/2017, here is an ES7 implementation (runs with babel preset stage 0, 1, 2, or 3):
const getUrlParams = url => `${url}?`.split('?')[1]
.split('&').reduce((params, pair) =>
((key, val) => key ? {...params, [key]: val} : params)
(...`${pair}=`.split('=').map(decodeURIComponent)), {});
Some tests:
console.log(getUrlParams('https://google.com/foo?a=1&b=2&c')); // Will log {a: '1', b: '2', c: ''}
console.log(getUrlParams('/foo?a=1&b=2&c')); // Will log {a: '1', b: '2', c: ''}
console.log(getUrlParams('?a=1&b=2&c')); // Will log {a: '1', b: '2', c: ''}
console.log(getUrlParams('https://google.com/')); // Will log {}
console.log(getUrlParams('a=1&b=2&c')); // Will log {}
Update 3/26/2018, here is a Typescript implementation:
const getUrlParams = (search: string) => `${search}?`
.split('?')[1]
.split('&')
.reduce(
(params: object, pair: string) => {
const [key, value] = `${pair}=`
.split('=')
.map(decodeURIComponent)
return key.length > 0 ? { ...params, [key]: value } : params
},
{}
)
Update 2/13/2019, here is an updated TypeScript implementation that works with TypeScript 3.
interface IParams { [key: string]: string }
const paramReducer = (params: IParams, pair: string): IParams => {
const [key, value] = `${pair}=`.split('=').map(decodeURIComponent)
return key.length > 0 ? { ...params, [key]: value } : params
}
const getUrlParams = (search: string): IParams =>
`${search}?`.split('?')[1].split('&').reduce<IParams>(paramReducer, {})

See this
function getURLParameters(paramName)
{
var sURL = window.document.URL.toString();
if (sURL.indexOf("?") > 0)
{
var arrParams = sURL.split("?");
var arrURLParams = arrParams[1].split("&");
var arrParamNames = new Array(arrURLParams.length);
var arrParamValues = new Array(arrURLParams.length);
var i = 0;
for (i = 0; i<arrURLParams.length; i++)
{
var sParam = arrURLParams[i].split("=");
arrParamNames[i] = sParam[0];
if (sParam[1] != "")
arrParamValues[i] = unescape(sParam[1]);
else
arrParamValues[i] = "No Value";
}
for (i=0; i<arrURLParams.length; i++)
{
if (arrParamNames[i] == paramName)
{
//alert("Parameter:" + arrParamValues[i]);
return arrParamValues[i];
}
}
return "No Parameters Found";
}
}

The shortest way:
new URL(location.href).searchParams.get("my_key");

ECMAScript 6 solution:
var params = window.location.search
.substring(1)
.split("&")
.map(v => v.split("="))
.reduce((map, [key, value]) => map.set(key, decodeURIComponent(value)), new Map())

I use the parseUri library. It allows you to do exactly what you are asking for:
var uri = 'www.test.com/t.html&a=1&b=3&c=m2-m3-m4-m5';
var c = uri.queryKey['c'];
// c = 'm2-m3-m4-m5'

I use
function getVal(str) {
var v = window.location.search.match(new RegExp('(?:[\?\&]'+str+'=)([^&]+)'));
return v ? v[1] : null;
}

this question has too many answers, so i'm adding another one.
/**
* parses and returns URI query parameters
*
* #param {string} param parm
* #param {bool?} asArray if true, returns an array instead of a scalar
* #returns {Object|Array}
*/
function getURIParameter(param, asArray) {
return document.location.search.substring(1).split('&').reduce(function(p,c) {
var parts = c.split('=', 2).map(function(param) { return decodeURIComponent(param); });
if(parts.length == 0 || parts[0] != param) return (p instanceof Array) && !asArray ? null : p;
return asArray ? p.concat(parts.concat(true)[1]) : parts.concat(true)[1];
}, []);
}
usage:
getURIParameter("id") // returns the last id or null if not present
getURIParameter("id", true) // returns an array of all ids
this copes with empty parameters (those keys present without "=value"), exposure of both a scalar and array-based value retrieval API, as well as proper URI component decoding.

Here is my solution. As advised by Andy E while answering this question, it's not good for your script's performance if it's repeatedly building various regex strings, running loops etc just to get a single value. So, I've come up with a simpler script that returns all the GET parameters in a single object. You should call it just once, assign the result to a variable and then, at any point in the future, get any value you want from that variable using the appropriate key. Note that it also takes care of URI decoding (i.e things like %20) and replaces + with a space:
function getUrlQueryParams(url) {
var queryString = url.split("?")[1];
var keyValuePairs = queryString.split("&");
var keyValue = [];
var queryParams = {};
keyValuePairs.forEach(function(pair) {
keyValue = pair.split("=");
queryParams[keyValue[0]] = decodeURIComponent(keyValue[1]).replace(/\+/g, " ");
});
return queryParams;
}
So, here are are a few tests of the script for you to see:
// Query parameters with strings only, no special characters.
var currentParams = getUrlQueryParams("example.com/foo?number=zero");
alert(currentParams["number"]); // Gives "zero".
// For the URL you stated above...
var someParams = getUrlQueryParams("www.test.com/t.html?a=1&b=3&c=m2-m3-m4-m5 ");
alert(someParams["c"]); // Gives "m2-m3-m4-m5".
// For a query params with URI encoding...
var someParams = getUrlQueryParams("www.example.com/t.html?phrase=a%20long%20shot&location=Silicon+Valley%2C+USA");
alert(someParams["phrase"]); // Gives "a long shot".
alert(someParams["location"]); // Gives "Silicon Valley, USA".

The easiest way using the replace() method:
From the urlStr string:
paramVal = urlStr.replace(/.*param_name=([^&]*).*|(.*)/, '$1');
or from the current URL:
paramVal = document.URL.replace(/.*param_name=([^&]*).*|(.*)/, '$1');
Explanation:
document.URL - interface returns the document location (page url) as a string.
replace() - method returns a new string with some or all matches of a pattern replaced by a replacement.
/.*param_name=([^&]*).*/ - the regular expression pattern enclosed between slashes which means:
.* - zero or more of any characters,
param_name= - param name which is serched,
() - group in regular expression,
[^&]* - one or more of any characters excluding &,
| - alternation,
$1 - reference to first group in regular expression.
var urlStr = 'www.test.com/t.html?a=1&b=3&c=m2-m3-m4-m5';
var c = urlStr.replace(/.*c=([^&]*).*|(.*)/, '$1');
var notExisted = urlStr.replace(/.*not_existed=([^&]*).*|(.*)/, '$1');
console.log(`c === '${c}'`);
console.log(`notExisted === '${notExisted}'`);

Yet another suggestion.
There are some good answers already, but I found them needlessly complex and hard to understand. This is short, simple, and returns a simple associative array with key names corresponding to the token names in the URL.
I added a version with comments below for those who want to learn.
Note this relies on jQuery ($.each) for its loop, which I recommend instead of forEach. I find it simpler to ensure cross-browser compatibility using jQuery across the board rather than plugging in individual fixes to support whichever new functions aren't supported in older browsers.
Edit: After I wrote this I noticed Eric Elliott's answer, which is almost the same, though it uses forEach, while I'm generally against (for reasons stated above).
function getTokens(){
var tokens = [];
var query = location.search;
query = query.slice(1);
query = query.split('&');
$.each(query, function(i,value){
var token = value.split('=');
var key = decodeURIComponent(token[0]);
var data = decodeURIComponent(token[1]);
tokens[key] = data;
});
return tokens;
}
Commented version:
function getTokens(){
var tokens = []; // new array to hold result
var query = location.search; // everything from the '?' onward
query = query.slice(1); // remove the first character, which will be the '?'
query = query.split('&'); // split via each '&', leaving us an array of something=something strings
// iterate through each something=something string
$.each(query, function(i,value){
// split the something=something string via '=', creating an array containing the token name and data
var token = value.split('=');
// assign the first array element (the token name) to the 'key' variable
var key = decodeURIComponent(token[0]);
// assign the second array element (the token data) to the 'data' variable
var data = decodeURIComponent(token[1]);
tokens[key] = data; // add an associative key/data pair to our result array, with key names being the URI token names
});
return tokens; // return the array
}
For the examples below we'll assume this address:
http://www.example.com/page.htm?id=4&name=murray
You can assign the URL tokens to your own variable:
var tokens = getTokens();
Then refer to each URL token by name like this:
document.write( tokens['id'] );
This would print "4".
You can also simply refer to a a token name from the function directly:
document.write( getTokens()['name'] );
...which would print "murray".

Or if you don't want to reinvent the URI parsing wheel use URI.js
To get the value of a parameter named foo:
new URI((''+document.location)).search(true).foo
What that does is
Convert document.location to a string (it's an object)
Feed that string to URI.js's URI class construtor
Invoke the search() function to get the search (query) portion of the url
(passing true tells it to output an object)
Access the foo property on the resulting object to get the value
Here's a fiddle for this.... http://jsfiddle.net/m6tett01/12/

For Single Parameter Value like this index.html?msg=1 use following code,
$(window).load(function(){
queryString();
});
function queryString()
{
var queryString = window.location.search.substring(1);
var varArray = queryString.split("="); //eg. index.html?msg=1
var param1 = varArray[0];
var param2 = varArray[1];
}
For All Parameter Value use following Code,
$(window).load(function(){
queryString();
});
function queryString()
{
var queryString = window.location.search;
var varArray = queryString.split("&");
for (var i=0;i<varArray.length;i++) {
var param = varArray[i].split("=");
//parameter-value pair
}
}

Here I am posting one example. But it's in jQuery. Hope it will help others:
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery.url.js"></script>
<!-- URL: www.example.com/correct/?message=done&year=1990-->
<script type="text/javascript">
$(function(){
$.url.attr('protocol') // --> Protocol: "http"
$.url.attr('path') // --> host: "www.example.com"
$.url.attr('query') // --> path: "/correct/"
$.url.attr('message') // --> query: "done"
$.url.attr('year') // --> query: "1990"
});
</script>

I had the need to read a URL GET variable and complete an action based on the url parameter. I searched high and low for a solution and came across this little piece of code. It basically reads the current page url, perform some regular expression on the URL then saves the url parameters in an associative array, which we can easily access.
So as an example if we had the following url with the javascript at the bottom in place.
http://TestServer/Pages/NewsArchive.aspx?year=2013&Month=July
All we’d need to do to get the parameters id and page are to call this:
The Code will be:
<script type="text/javascript">
var first = getUrlVars()["year"];
var second = getUrlVars()["Month"];
alert(first);
alert(second);
function getUrlVars() {
var vars = {};
var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m,key,value) {
vars[key] = value;
});
return vars;
}
</script>

// Read a page's GET URL variables and return them as an associative array.
function getUrlVars()
{
var vars = [], hash;
var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
for(var i = 0; i < hashes.length; i++)
{
hash = hashes[i].split('=');
vars.push(hash[0]);
vars[hash[0]] = hash[1];
}
return vars;
}
// Usage for URL: http://my.site.com/location?locationId=53cc272c0364aefcb78756cd&shared=false
var id = getUrlVars()["locationId"];
Got from here: http://jquery-howto.blogspot.ru/2009/09/get-url-parameters-values-with-jquery.html

Simple way
function getParams(url){
var regex = /[?&]([^=#]+)=([^&#]*)/g,
params = {},
match;
while(match = regex.exec(url)) {
params[match[1]] = match[2];
}
return params;
}
then call it like getParams(url)

Elegant, functional style solution
Let's create an object containing URL param names as keys, then we can easily extract the parameter by its name:
// URL: https://example.com/?test=true&orderId=9381
// Build an object containing key-value pairs
export const queryStringParams = window.location.search
.split('?')[1]
.split('&')
.map(keyValue => keyValue.split('='))
.reduce<QueryStringParams>((params, [key, value]) => {
params[key] = value;
return params;
}, {});
type QueryStringParams = {
[key: string]: string;
};
// Return URL parameter called "orderId"
return queryStringParams.orderId;

It's the N++ time I am looking for a clean way to do this.
Will save this here in case I get back cause I know I will... 🙄
const parseUrlQuery = (value) => {
var urlParams = new URL(value).searchParams
return Array.from(urlParams.keys()).reduce((acc, key) => {
acc[key] = urlParams.getAll(key)
return acc
}, {})
}
console.log(parseUrlQuery('http://url/path?param1=A&param1=B&param2=ABC&param3=61569'))

Here is what I do:
var uriParams = getSearchParameters();
alert(uriParams.c);
// background functions:
// 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;
}

// http:localhost:8080/path?param_1=a&param_2=b
var getParamsMap = function () {
var params = window.location.search.split("&");
var paramsMap = {};
params.forEach(function (p) {
var v = p.split("=");
paramsMap[v[0]]=decodeURIComponent(v[1]);
});
return paramsMap;
};
// -----------------------
console.log(getParamsMap()["param_1"]); // should log "a"

JavaScript get url segment and parameter

I've read some question but I still can't figure out how to do it
I have a url example.com/event/14aD9Uxp?p=10
Here I want to get the 14aD9Uxp and the value of p
I've tried using split('/'+'?p=') but it doesn't work
I want to use regex but I dont really understand how to use it

var URL='example.com/event/14aD9Uxp?p=10';
var arr=URL.split('/');//arr[0]='example.com'
//arr[1]='event'
//arr[2]='14aD9Uxp?p=10'
var parameter=arr[arr.length-1].split('?');//parameter[0]='14aD9Uxp'
//parameter[1]='p=10'
var p_value=parameter[1].split('=')[1];//p_value='10';

I've created a generalized function (restricted in some ways) that will return the GET value given the parameter. However this function will only work correctly provided that you do not Rewrite the URL or modify the URL GET SYNTAX.
//Suppose this is your URL "example.com/event/14aD9Uxp?p=10";
function GET(variable) {
var str = window.location.href;
str = str.split("/");
// str = [example.com, event, 14aD9Uxp?p=10]
//Get last item from array because this is usually where the GET parameter is located, then split with "?"
str = str[str.length - 1].split("?");
// str[str.length - 1] = "14aD9Uxp?p=10"
// str[str.length - 1].split("?") = [14aD9Uxp, p=10]
// If there is more than 1 GET parameter, they usually connected with Ampersand symbol (&). Assuming there is more, we need to split this into another array
str = str[1].split("&");
// Suppose this is your URL: example.com/event/14aD9Uxp?p=10&q=112&r=119
// str = [p=10, q=112, r=119]
// If there is only 1 GET parameter, this split() function will not "split" anything
//Remember, there might only be 1 GET Parameter, so lets check length of the array to be sure.
if (str.length > 1) {
// This is the case where there is more than 1 parameter, so we loop over the array and filter out the variable requested
for (var i = 0; i < str.length; i++) {
// For each "p=10" etc. split the equal sign
var param_full_str = str[i].split("=");
// param_full_str = [p, 10]
//Check if the first item in the array (your GET parameter) is equal to the parameter requested
if (param_full_str[0] == variable) {
// If it is equal, return the second item in the array, your GET parameter VALUE
return param_full_str[1];
}
}
} else {
// This is the case where there is ONLY 1 GET parameter. First convert it to a String Type because Javascript decided that str was no longer a String
// Now split it with the equal sign.
str = str.toString().split("=");
return str[1];
}
}
document.write(GET("p"));

function $_GET(param) {
var vars = {};
window.location.href.replace(
/[?&]+([^=&]+)=?([^&]*)?/gi, // regexp
function( m, key, value ) { // callback
vars[key] = value !== undefined ? value : '';
}
);
if ( param ) {
return vars[param] ? vars[param] : null;
}
return vars;
}
I have collected this from here:
http://www.creativejuiz.fr/blog/javascript/recuperer-parametres-get-url-javascript
It works great.
To use it just grab your parameter like:
var id = $_GET('id');

const url = new URL('http://example.com/event/14aD9Uxp?p=10');
const [,, eventId ] = url.pathname.split('/');
const p = url.searchParams.get('p');
Browser support:
https://caniuse.com/#feat=url
https://caniuse.com/#feat=urlsearchparams

Simple no-regex way
var s = "example.com/event/14aD9Uxp?p=10";
var splitByForwardSlash = s.split('/');
// To get 14aD9Uxp
splitByForwardSlash[splitByForwardSlash.length-1]
// To get p=10
splitByForwardSlash[splitByForwardSlash.length-1].split('?')[1]
I think you know how to go from here :-)

Get Query String with Dojo

Users will be hitting up against a URL that contains a query string called inquirytype. For a number of reasons, I need to read in this query string with javascript (Dojo) and save its value to a variable. I've done a fair amount of research trying to find how to do this, and I've discovered a few possibilities, but none of them seem to actually read in a query string that isn't hard-coded somewhere in the script.

You can access parameters from the url using location.search without Dojo Can a javascript attribute value be determined by a manual url parameter?
function getUrlParams() {
var paramMap = {};
if (location.search.length == 0) {
return paramMap;
}
var parts = location.search.substring(1).split("&");
for (var i = 0; i < parts.length; i ++) {
var component = parts[i].split("=");
paramMap [decodeURIComponent(component[0])] = decodeURIComponent(component[1]);
}
return paramMap;
}
Then you could do the following to extract id from the url /hello.php?id=5&name=value
var params = getUrlParams();
var id = params['id']; // or params.id
Dojo provides http://dojotoolkit.org/reference-guide/dojo/queryToObject.html which is a bit smarter than my simple implementation and creates arrays out of duplicated keys.
var uri = "http://some.server.org/somecontext/?foo=bar&foo=bar2&bit=byte";
var query = uri.substring(uri.indexOf("?") + 1, uri.length);
var queryObject = dojo.queryToObject(query);
//The structure of queryObject will be:
// {
// foo: ["bar", "bar2],
// bit: "byte"
// }

In new dojo it's accessed with io-query:
require([
"dojo/io-query",
], function (ioQuery) {
GET = ioQuery.queryToObject(decodeURIComponent(dojo.doc.location.search.slice(1)));
console.log(GET.id);
});

Since dojo 0.9, there is a better option, queryToObject.
dojo.queryToObject(query)
See this similar question with what I think is a cleaner answer.

How to get "GET" request parameters in JavaScript? [duplicate]

This question already has answers here:
How can I get query string values in JavaScript?
(73 answers)
Closed 1 year ago.
How to get "GET" variables from request in JavaScript?
Does jQuery or YUI! have this feature built-in?

Update June 2021:
Today's browsers have built-in APIs for working with URLs (URL) and query strings (URLSearchParams) and these should be preferred, unless you need to support some old browsers or Opera mini (Browser support).
Original:
All data is available under
window.location.search
you have to parse the string, eg.
function get(name){
if(name=(new RegExp('[?&]'+encodeURIComponent(name)+'=([^&]*)')).exec(location.search))
return decodeURIComponent(name[1]);
}
just call the function with GET variable name as parameter, eg.
get('foo');
this function will return the variables value or undefined if variable has no value or doesn't exist

You could use jquery.url I did like this:
var xyz = jQuery.url.param("param_in_url");
Check the source code
Updated Source: https://github.com/allmarkedup/jQuery-URL-Parser

try the below code, it will help you get the GET parameters from url .
for more details.
var url_string = window.location.href; // www.test.com?filename=test
var url = new URL(url_string);
var paramValue = url.searchParams.get("filename");
alert(paramValue)

Just to put my two cents in, if you wanted an object containing all the requests
function getRequests() {
var s1 = location.search.substring(1, location.search.length).split('&'),
r = {}, s2, i;
for (i = 0; i < s1.length; i += 1) {
s2 = s1[i].split('=');
r[decodeURIComponent(s2[0]).toLowerCase()] = decodeURIComponent(s2[1]);
}
return r;
};
var QueryString = getRequests();
//if url === "index.html?test1=t1&test2=t2&test3=t3"
console.log(QueryString["test1"]); //logs t1
console.log(QueryString["test2"]); //logs t2
console.log(QueryString["test3"]); //logs t3
Note, the key for each get param is set to lower case. So, I made a helper function. So now it's case-insensitive.
function Request(name){
return QueryString[name.toLowerCase()];
}

Unlike other answers, the UrlSearchParams object can avoid using Regexes or other string manipulation and is available is most modern browsers:
var queryString = location.search
let params = new URLSearchParams(queryString)
// example of retrieving 'id' parameter
let id = parseInt(params.get("id"))
console.log(id)

You can use the URL to acquire the GET variables. In particular, window.location.search gives everything after (and including) the '?'. You can read more about window.location here.

A map-reduce solution:
var urlParams = location.search.split(/[?&]/).slice(1).map(function(paramPair) {
return paramPair.split(/=(.+)?/).slice(0, 2);
}).reduce(function (obj, pairArray) {
obj[pairArray[0]] = pairArray[1];
return obj;
}, {});
Usage:
For url: http://example.com?one=1&two=2
console.log(urlParams.one) // 1
console.log(urlParams.two) // 2

Today I needed to get the page's request parameters into a associative array so I put together the following, with a little help from my friends. It also handles parameters without an = as true.
With an example:
// URL: http://www.example.com/test.php?abc=123&def&xyz=&something%20else
var _GET = (function() {
var _get = {};
var re = /[?&]([^=&]+)(=?)([^&]*)/g;
while (m = re.exec(location.search))
_get[decodeURIComponent(m[1])] = (m[2] == '=' ? decodeURIComponent(m[3]) : true);
return _get;
})();
console.log(_GET);
> Object {abc: "123", def: true, xyz: "", something else: true}
console.log(_GET['something else']);
> true
console.log(_GET.abc);
> 123

You can parse the URL of the current page to obtain the GET parameters. The URL can be found by using location.href.

If you already use jquery there is a jquery plugin that handles this:
http://plugins.jquery.com/project/query-object

The function here returns the parameter by name. With tiny changes you will be able to return base url, parameter or anchor.
function getUrlParameter(name) {
var urlOld = window.location.href.split('?');
urlOld[1] = urlOld[1] || '';
var urlBase = urlOld[0];
var urlQuery = urlOld[1].split('#');
urlQuery[1] = urlQuery[1] || '';
var parametersString = urlQuery[0].split('&');
if (parametersString.length === 1 && parametersString[0] === '') {
parametersString = [];
}
// console.log(parametersString);
var anchor = urlQuery[1] || '';
var urlParameters = {};
jQuery.each(parametersString, function (idx, parameterString) {
paramName = parameterString.split('=')[0];
paramValue = parameterString.split('=')[1];
urlParameters[paramName] = paramValue;
});
return urlParameters[name];
}

Works for me in
url: http://localhost:8080/#/?access_token=111
function get(name){
const parts = window.location.href.split('?');
if (parts.length > 1) {
name = encodeURIComponent(name);
const params = parts[1].split('&');
const found = params.filter(el => (el.split('=')[0] === name) && el);
if (found.length) return decodeURIComponent(found[0].split('=')[1]);
}
}