Query-string encoding of a Javascript Object

Query-string encoding of a Javascript Object

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 other frameworks – just plain Javascript 🙂

Solutions/Answers:

Solution 1:

like this?

serialize = function(obj) {
  var str = [];
  for (var p in obj)
    if (obj.hasOwnProperty(p)) {
      str.push(encodeURIComponent(p) + "=" + encodeURIComponent(obj[p]));
    }
  return str.join("&");
}

console.log(serialize({
  foo: "hi there",
  bar: "100%"
}));
// foo=hi%20there&bar=100%25

Edit: this one also converts recursive objects (using php “array” notation for the query string)

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

console.log(serialize({
  foo: "hi there",
  bar: {
    blah: 123,
    quux: [1, 2, 3]
  }
}));
// foo=hi%20there&bar%5Bblah%5D=123&bar%5Bquux%5D%5B0%5D=1&bar%5Bquux%5D%5B1%5D=2&bar%5Bquux%5D%5B2%5D=3

Solution 2:

jQuery has a function for this, jQuery.param(), if you’re already using it you can use that:
http://api.jquery.com/jquery.param/

example:

var params = { width:1680, height:1050 };
var str = jQuery.param( params );

str now contains width=1680&height=1050

Solution 3:

Object.keys(obj).reduce(function(a,k){a.push(k+'='+encodeURIComponent(obj[k]));return a},[]).join('&')

Edit: I like this one-liner, but I bet it would be a more popular answer if it matched the accepted answer semantically:

function serialize( obj ) {
    let str = '?' + Object.keys(obj).reduce(function(a, k){
        a.push(k + '=' + encodeURIComponent(obj[k]));
        return a;
    }, []).join('&');
    return str;
}

Solution 4:

Here’s a one liner in ES6:

Object.keys(obj).map(k => `${encodeURIComponent(k)}=${encodeURIComponent(obj[k])}`).join('&');

Solution 5:

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

Solution 6:

I suggest using the URLSearchParams interface:

const searchParams = new URLSearchParams();
const search = {foo: "hi there", bar: "100%" };
Object.keys(search).forEach(key => searchParams.append(key, search[key]));
console.log(searchParams.toString())