Query-string encoding of a Javascript Object

Question

Do you know a fast and simple way to encode a Javascript Object into a string that I can pass via a GET Request?

No jQuery, no

Answer 1

A little bit look better

objectToQueryString(obj, prefix) {
    return Object.keys(obj).map(objKey => {
        if (obj.hasOwnProperty(objKey)) {
            const key = prefix ? `${prefix}[${objKey}]` : objKey;
            const value = obj[objKey];

            return typeof value === "object" ?
                this.objectToQueryString(value, key) :
                `${encodeURIComponent(key)}=${encodeURIComponent(value)}`;
        }

        return null;
    }).join("&");
}

Answer 2

Well, everyone seems to put his one-liner here so here goes mine:

const encoded = Object.entries(obj).map(([k, v]) => `${k}=${encodeURIComponent(v)}`).join("&");

Answer 3

I have a simpler solution that does not use any third-party library and is already apt to be used in any browser that has "Object.keys" (aka all modern browsers + edge + ie):

In ES5

function(a){
    if( typeof(a) !== 'object' ) 
        return '';
    return `?${Object.keys(a).map(k=>`${k}=${a[k]}`).join('&')}`;
}

In ES3

function(a){
    if( typeof(a) !== 'object' ) 
        return '';
    return '?' + Object.keys(a).map(function(k){ return k + '=' + a[k] }).join('&');
}

Answer 4

ok, it's a older post but i'm facing this problem and i have found my personal solution.. maybe can help someone else..

     function objToQueryString(obj){
        var k = Object.keys(obj);
        var s = "";
        for(var i=0;i<k.length;i++) {
            s += k[i] + "=" + encodeURIComponent(obj[k[i]]);
            if (i != k.length -1) s += "&";
        }
        return s;
     };

Answer 5

Addition for accepted solution, this works with objects & array of objects:

parseJsonAsQueryString = function (obj, prefix, objName) {
    var str = [];
    for (var p in obj) {
        if (obj.hasOwnProperty(p)) {
            var v = obj[p];
            if (typeof v == "object") {
                var k = (objName ? objName + '.' : '') + (prefix ? prefix + "[" + p + "]" : p);
                str.push(parseJsonAsQueryString(v, k));
            } else {
                var k = (objName ? objName + '.' : '') + (prefix ? prefix + '.' + p : p);
                str.push(encodeURIComponent(k) + "=" + encodeURIComponent(v));
                //str.push(k + "=" + v);
            }
        }
    }
    return str.join("&");
}

Also have added objName if you're using object parameters like in asp.net mvc action methods.

Answer 6

With Node.js v6.6.3

const querystring = require('querystring')

const obj = {
  foo: 'bar',
  baz: 'tor'
}

let result = querystring.stringify(obj)
// foo=bar&baz=tor

Reference: https://nodejs.org/api/querystring.html