How to get URL parameter using jQuery or plain JavaScript?

jQuery code snippet to get the dynamic variables stored in the url as parameters and store them as JavaScript variables ready for use with your scripts:

$.urlParam = function(name){
    var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);
    if (results==null) {
       return null;
    }
    return decodeURI(results[1]) || 0;
}

example.com?param1=name&param2=&id=6

$.urlParam('param1'); // name
$.urlParam('id');        // 6
$.urlParam('param2');   // null

example params with spaces

http://www.jquery4u.com?city=Gold Coast
console.log($.urlParam('city'));  
//output: Gold%20Coast



console.log(decodeURIComponent($.urlParam('city'))); 
//output: Gold Coast

I always stick this as one line. Now params has the vars:

params={};location.search.replace(/[?&]+([^=&]+)=([^&]*)/gi,function(s,k,v){params[k]=v})

multi-lined:

var params={};
window.location.search
  .replace(/[?&]+([^=&]+)=([^&]*)/gi, function(str,key,value) {
    params[key] = value;
  }
);

as a function

function getSearchParams(k){
 var p={};
 location.search.replace(/[?&]+([^=&]+)=([^&]*)/gi,function(s,k,v){p[k]=v})
 return k?p[k]:p;
}

which you could use as:

getSearchParams()  //returns {key1:val1, key2:val2}

or

getSearchParams("key1")  //returns val1

Yet another alternative function...

function param(name) {
    return (location.search.split(name + '=')[1] || '').split('&')[0];
}

May be its too late. But this method is very easy and simple

<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"
});

UPDATE
Requires the url plugin : plugins.jquery.com/url
Thanks -Ripounet

Or you can use this neat little function, because why overcomplicated solutions?

function getQueryParam(param, defaultValue = undefined) {
    location.search.substr(1)
        .split("&")
        .some(function(item) { // returns first occurence and stops
            return item.split("=")[0] == param && (defaultValue = item.split("=")[1], true)
        })
    return defaultValue
}

which looks even better when simplified and onelined:

tl;dr one-line solution

var queryDict = {};
location.search.substr(1).split("&").forEach(function(item) {queryDict[item.split("=")[0]] = item.split("=")[1]})

result:
queryDict['sent'] // undefined or 'value'

But what if you have got encoded characters or multivalued keys?

You better see this answer: How can I get query string values in JavaScript?

Sneak peak

"?a=1&b=2&c=3&d&e&a=5&a=t%20e%20x%20t&e=http%3A%2F%2Fw3schools.com%2Fmy%20test.asp%3Fname%3Dståle%26car%3Dsaab"
> queryDict
a: ["1", "5", "t e x t"]
b: ["2"]
c: ["3"]
d: [undefined]
e: [undefined, "http://w3schools.com/my test.asp?name=ståle&car=saab"]

> queryDict["a"][1] // "5"
> queryDict.a[1] // "5"