How to convert URL parameters to a JavaScript object?

Question

I have a string like this:

abc=foo&def=%5Basf%5D&xyz=5

How can I convert it into a JavaScript object like this?

{
          


        

Answer 1

I needed to also deal with + in the query part of the URL (decodeURIComponent doesn't), so I adapted Wolfgang's code to become:

var search = location.search.substring(1);
search = search?JSON.parse('{"' + search.replace(/\+/g, ' ').replace(/&/g, '","').replace(/=/g,'":"') + '"}',
             function(key, value) { return key===""?value:decodeURIComponent(value)}):{};

In my case, I'm using jQuery to get URL-ready form parameters, then this trick to build an object out of it and I can then easily update parameters on the object and rebuild the query URL, e.g.:

var objForm = JSON.parse('{"' + $myForm.serialize().replace(/\+/g, ' ').replace(/&/g, '","').replace(/=/g,'":"') + '"}',
             function(key, value) { return key===""?value:decodeURIComponent(value)});
objForm.anyParam += stringToAddToTheParam;
var serializedForm = $.param(objForm);

Answer 2

The proposed solutions I found so far do not cover more complex scenarios.

I needed to convert a query string like

https://random.url.com?Target=Offer&Method=findAll&filters%5Bhas_goals_enabled%5D%5BTRUE%5D=1&filters%5Bstatus%5D=active&fields%5B%5D=id&fields%5B%5D=name&fields%5B%5D=default_goal_name

into an object like:

{
    "Target": "Offer",
    "Method": "findAll",
    "fields": [
        "id",
        "name",
        "default_goal_name"
    ],
    "filters": {
        "has_goals_enabled": {
            "TRUE": "1"
        },
        "status": "active"
    }
}

OR:

https://random.url.com?Target=Report&Method=getStats&fields%5B%5D=Offer.name&fields%5B%5D=Advertiser.company&fields%5B%5D=Stat.clicks&fields%5B%5D=Stat.conversions&fields%5B%5D=Stat.cpa&fields%5B%5D=Stat.payout&fields%5B%5D=Stat.date&fields%5B%5D=Stat.offer_id&fields%5B%5D=Affiliate.company&groups%5B%5D=Stat.offer_id&groups%5B%5D=Stat.date&filters%5BStat.affiliate_id%5D%5Bconditional%5D=EQUAL_TO&filters%5BStat.affiliate_id%5D%5Bvalues%5D=1831&limit=9999

INTO:

{
    "Target": "Report",
    "Method": "getStats",
    "fields": [
        "Offer.name",
        "Advertiser.company",
        "Stat.clicks",
        "Stat.conversions",
        "Stat.cpa",
        "Stat.payout",
        "Stat.date",
        "Stat.offer_id",
        "Affiliate.company"
    ],
    "groups": [
        "Stat.offer_id",
        "Stat.date"
    ],
    "limit": "9999",
    "filters": {
        "Stat.affiliate_id": {
            "conditional": "EQUAL_TO",
            "values": "1831"
        }
    }
}

I compiled and adapted multiple solutions into one that actually works:

CODE:

var getParamsAsObject = function (query) {

    query = query.substring(query.indexOf('?') + 1);

    var re = /([^&=]+)=?([^&]*)/g;
    var decodeRE = /\+/g;

    var decode = function (str) {
        return decodeURIComponent(str.replace(decodeRE, " "));
    };

    var params = {}, e;
    while (e = re.exec(query)) {
        var k = decode(e[1]), v = decode(e[2]);
        if (k.substring(k.length - 2) === '[]') {
            k = k.substring(0, k.length - 2);
            (params[k] || (params[k] = [])).push(v);
        }
        else params[k] = v;
    }

    var assign = function (obj, keyPath, value) {
        var lastKeyIndex = keyPath.length - 1;
        for (var i = 0; i < lastKeyIndex; ++i) {
            var key = keyPath[i];
            if (!(key in obj))
                obj[key] = {}
            obj = obj[key];
        }
        obj[keyPath[lastKeyIndex]] = value;
    }

    for (var prop in params) {
        var structure = prop.split('[');
        if (structure.length > 1) {
            var levels = [];
            structure.forEach(function (item, i) {
                var key = item.replace(/[?[\]\\ ]/g, '');
                levels.push(key);
            });
            assign(params, levels, params[prop]);
            delete(params[prop]);
        }
    }
    return params;
};

Answer 3

I found $.String.deparam the most complete pre built solution (can do nested objects etc.). Check out the documentation.

Answer 4

This is the simple version, obviously you'll want to add some error checking:

var obj = {};
var pairs = queryString.split('&');
for(i in pairs){
    var split = pairs[i].split('=');
    obj[decodeURIComponent(split[0])] = decodeURIComponent(split[1]);
}

Answer 5

There is no native solution that I'm aware of. Dojo has a built-in unserialization method if you use that framework by chance.

Otherwise you can implement it yourself rather simply:

function unserialize(str) {
  str = decodeURIComponent(str);
  var chunks = str.split('&'),
      obj = {};
  for(var c=0; c < chunks.length; c++) {
    var split = chunks[c].split('=', 2);
    obj[split[0]] = split[1];
  }
  return obj;
}

edit: added decodeURIComponent()

Answer 6

Using ES6, URL API and URLSearchParams API.

function objectifyQueryString(url) {
  let _url = new URL(url);
  let _params = new URLSearchParams(_url.search);
  let query = Array.from(_params.keys()).reduce((sum, value)=>{
    return Object.assign({[value]: _params.get(value)}, sum);
  }, {});
  return query;
}