you can simply use javascript function

 JSON.parse('{ "employees" : [' +
 '{ "firstName":"John" , "lastName":"Doe" },' +
 '{ "firstName":"Anna" , "lastName":"Smith" },' +
 '{ "firstName":"Peter" , "lastName":"Jones" } ]}');

I don't know why, but I found only one really working solution for form with inputs with names like name="some[sub][sub][sub][name]".

There is it: LINK

Here's a non-jQuery way:

    var getFormData = function(form) {
        //Ignore the submit button
        var elements = Array.prototype.filter.call(form.elements, function(element) {
            var type = element.getAttribute('type');
            return !type || type.toLowerCase() !== 'submit';
        });

You can use it like this:

function() {

    var getFormData = function(form) {
        //Ignore the submit button
        var elements = Array.prototype.filter.call(form.elements, function(element) {
            var type = element.getAttribute('type');
            return !type || type.toLowerCase() !== 'submit';
        });

        //Make an object out of the form data: {name: value}
        var data = elements.reduce(function(data, element) {
            data[element.name] = element.value;
            return data;
        }, {});

        return data;
    };

    var post = function(action, data, callback) {
        var request = new XMLHttpRequest();
        request.onload = callback;
        request.open('post', action);
        request.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
        request.send(JSON.stringify(data), true);
        request.send();
    };

    var submit = function(e) {
        e.preventDefault();
        var form = e.target;
        var action = form.action;
        var data = getFormData(form);
        //change the third argument in order to do something
        //more intersting with the response than just print it
        post(action, data, console.log.bind(console));
    }

    //change formName below
    document.formName.onsubmit = submit;

})();

From some older answer:

$('form input,select').toArray().reduce(function(m,e){m[e.name] = $(e).val(); return m;},{})

If you want to convert a form to a javascript object, then the easiest solution (at this time) is to use jQuery's each and serializeArray function-methods.

$.fn.serializeObject = function() {

  var form = {};
  $.each($(this).serializeArray(), function (i, field) {
    form[field.name] = field.value || "";
  });

  return form;
};

Plugin hosted on GitHub:
https://github.com/tfmontague/form-object/blob/master/README.md

Can be installed with Bower:
bower install git://github.com/tfmontague/form-object.git

I recently had the same problem so I developed a function that allows parsing a form's controls to obtain control id/value and convert that to JSON.

It is flexible enough to allow adding more controls. You just need to specify the control type and the attribute that you want to interpreted as value.

You can find the full script here.

The advantage is that it only takes the data you actually need, without dragging the whole object.

The dissadvantage is that if you have nested options, you need to prefix the IDs accordingly so you can use a duplicate option to its specific group.

I hope this helps!

I like using Array.prototype.reduce because it's a one-liner, and it doesn't rely on Underscore.js or the like:

$('#formid').serializeArray()
    .reduce(function(a, x) { a[x.name] = x.value; return a; }, {});

This is similar to the answer using Array.prototype.map, but you don't need to clutter up your scope with an additional object variable. One-stop shopping.

IMPORTANT NOTE: Forms with inputs that have duplicate name attributes are valid HTML, and is actually a common approach. Using any of the answers in this thread will be inappropriate in that case (since object keys must be unique).

If you are sending a form with JSON you must remove [] in sending the string. You can do that with the jQuery function serializeObject():

var frm = $(document.myform);
var data = JSON.stringify(frm.serializeObject());

$.fn.serializeObject = function() {
    var o = {};
    //var a = this.serializeArray();
    $(this).find('input[type="hidden"], input[type="text"], input[type="password"], input[type="checkbox"]:checked, input[type="radio"]:checked, select').each(function() {
        if ($(this).attr('type') == 'hidden') { //If checkbox is checked do not take the hidden field
            var $parent = $(this).parent();
            var $chb = $parent.find('input[type="checkbox"][name="' + this.name.replace(/\[/g, '\[').replace(/\]/g, '\]') + '"]');
            if ($chb != null) {
                if ($chb.prop('checked')) return;
            }
        }
        if (this.name === null || this.name === undefined || this.name === '')
            return;
        var elemValue = null;
        if ($(this).is('select'))
            elemValue = $(this).find('option:selected').val();
        else
            elemValue = this.value;
        if (o[this.name] !== undefined) {
            if (!o[this.name].push) {
                o[this.name] = [o[this.name]];
            }
            o[this.name].push(elemValue || '');
        }
        else {
            o[this.name] = elemValue || '';
        }
    });
    return o;
}

You can do this:

var frm = $(document.myform);
var data = JSON.stringify(frm.serializeArray());

See JSON in JavaScript.

There is a plugin to do just that for jQuery, jquery.serializeJSON. I have used it successfully on a few projects now. It works like a charm.

If you are using Underscore.js you can use the relatively concise:

_.object(_.map($('#myform').serializeArray(), _.values))

Using maček's solution, I modified it to work with the way ASP.NET MVC handles their nested/complex objects on the same form. All you have to do is modify the validate piece to this:

"validate": /^[a-zA-Z][a-zA-Z0-9_]*((?:\[(?:\d*|[a-zA-Z0-9_]+)\])*(?:\.)[a-zA-Z][a-zA-Z0-9_]*)*$/,

This will match and then correctly map elements with names like:

<input type="text" name="zooName" />

And

<input type="text" name="zooAnimals[0].name" />

Use:

function form_to_json (selector) {
  var ary = $(selector).serializeArray();
  var obj = {};
  for (var a = 0; a < ary.length; a++) obj[ary[a].name] = ary[a].value;
  return obj;
}

Output:

{"myfield": "myfield value", "passwordfield": "mypasswordvalue"}

I wrote a jQuery module, jsForm, that can do this bidirectional even for quite complicated forms (allows collections and other more complex structures as well).

It uses the name of the fields (plus a few special classes for collections) and matches a JSON object. It allows automatic replication of DOM-elements for collections and data handling:

<html>
    <head>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <script src="https://raw.github.com/corinis/jsForm/master/src/jquery.jsForm.js"></script>
        <script>
        $(function(){
            // Some JSON data
            var jsonData = {
                name: "TestName",   // Standard inputs
                description: "long Description\nMultiline", // Textarea
                links: [{href:'http://stackoverflow.com',description:'StackOverflow'}, {href:'http://www.github.com', description:'GitHub'}],   // Lists
                active: true,   // Checkbox
                state: "VISIBLE"    // Selects (enums)
            };

            // Initialize the form, prefix is optional and defaults to data
            $("#details").jsForm({
                data:jsonData
            });

            $("#show").click(function() {
                // Show the JSON data
                alert(JSON.stringify($("#details").jsForm("get"), null, " "));
            });
        });
        </script>
    </head>
    <body>
        <h1>Simpel Form Test</h1>
        <div id="details">
            Name: <input name="data.name"/><br/>
            <input type="checkbox" name="data.active"/> active<br/>
            <textarea name="data.description"></textarea><br/>
            <select name="data.state">
                <option value="VISIBLE">visible</option>
                <option value="IMPORTANT">important</option>
                <option value="HIDDEN">hidden</option>
            </select>
            <fieldset>
                <legend>Links</legend>
                <ul class="collection" data-field="data.links">
                    <li><span class="field">links.description</span> Link: <input name="links.href"/> <button class="delete">x</button></li>
                </ul>
            </fieldset>
            <button class="add" data-field="data.links">add a link</button><br/>
            Additional field: <input name="data.addedField"/>
        </div>
        <button id="show">Show Object</button>
    </body>
</html>

I coded a form to a multidimensional JavaScript object myself to use it in production. The result is https://github.com/serbanghita/formToObject.js.

Simplicity is best here. I've used a simple string replace with a regular expression, and they worked like a charm thus far. I am not a regular expression expert, but I bet you can even populate very complex objects.

var values = $(this).serialize(),
attributes = {};

values.replace(/([^&]+)=([^&]*)/g, function (match, name, value) {
    attributes[name] = value;
});

My code from my library phery got a serialization routine that can deal with really complex forms (like in the demo https://github.com/pocesar/phery/blob/master/demo.php#L1664 ), and it's not a one-size-fits-all. It actually checks what the type of each field is. For example, a radio box isn't the same as a range, that isn't the same as keygen, that isn't the same as select multiple. My function covers it all, and you can see it at https://github.com/pocesar/phery/blob/master/phery.js#L1851.

serializeForm:function (opt) {
    opt = $.extend({}, opt);

    if (typeof opt['disabled'] === 'undefined' || opt['disabled'] === null) {
        opt['disabled'] = false;
    }
    if (typeof opt['all'] === 'undefined' || opt['all'] === null) {
        opt['all'] = false;
    }
    if (typeof opt['empty'] === 'undefined' || opt['empty'] === null) {
        opt['empty'] = true;
    }

    var
        $form = $(this),
        result = {},
        formValues =
            $form
                .find('input,textarea,select,keygen')
                .filter(function () {
                    var ret = true;
                    if (!opt['disabled']) {
                        ret = !this.disabled;
                    }
                    return ret && $.trim(this.name);
                })
                .map(function () {
                    var
                        $this = $(this),
                        radios,
                        options,
                        value = null;

                    if ($this.is('[type="radio"]') || $this.is('[type="checkbox"]')) {
                        if ($this.is('[type="radio"]')) {
                            radios = $form.find('[type="radio"][name="' + this.name + '"]');
                            if (radios.filter('[checked]').size()) {
                                value = radios.filter('[checked]').val();
                            }
                        } else if ($this.prop('checked')) {
                            value = $this.is('[value]') ? $this.val() : 1;
                        }
                    } else if ($this.is('select')) {
                        options = $this.find('option').filter(':selected');
                        if ($this.prop('multiple')) {
                            value = options.map(function () {
                                return this.value || this.innerHTML;
                            }).get();
                        } else {
                            value = options.val();
                        }
                    } else {
                        value = $this.val();
                    }

                    return {
                        'name':this.name || null,
                        'value':value
                    };
                }).get();

    if (formValues) {
        var
            i,
            value,
            name,
            $matches,
            len,
            offset,
            j,
            fields;

        for (i = 0; i < formValues.length; i++) {
            name = formValues[i].name;
            value = formValues[i].value;

            if (!opt['all']) {
                if (value === null) {
                    continue;
                }
            } else {
                if (value === null) {
                    value = '';
                }
            }

            if (value === '' && !opt['empty']) {
                continue;
            }

            if (!name) {
                continue;
            }

            $matches = name.split(/\[/);

            len = $matches.length;

            for (j = 1; j < len; j++) {
                $matches[j] = $matches[j].replace(/\]/g, '');
            }

            fields = [];

            for (j = 0; j < len; j++) {
                if ($matches[j] || j < len - 1) {
                    fields.push($matches[j].replace("'", ''));
                }
            }

            if ($matches[len - 1] === '') {
                offset = assign_object(result, fields, [], true, false, false);

                if (value.constructor === Array) {
                    offset[0][offset[1]].concat(value);
                } else {
                    offset[0][offset[1]].push(value);
                }
            } else {
                assign_object(result, fields, value);
            }
        }
    }

    return result;
}

It's part of my library phery, but it can be ported to your own project. It creates arrays where there should be arrays, it gets the correct selected options from the select, normalize checkbox options, etc. If you want to convert it to JSON (a real JSON string), just do JSON.stringify($('form').serializeForm());

I had the same problem lately and came out with this .toJSON jQuery plugin which converts a form into a JSON object with the same structure. This is also expecially useful for dynamically generated forms where you want to let your user add more fields in specific places.

The point is you may actually want to build a form so that it has a structure itself, so let's say you want to make a form where the user inserts his favourite places in town: you can imagine this form to represent a <places>...</places> XML element containing a list of places the user likes thus a list of <place>...</place> elements each one containing for example a <name>...</name> element, a <type>...</type> element and then a list of <activity>...</activity> elements to represent the activities you can perform in such a place. So your XML structure would be like this:

<places>

    <place>

        <name>Home</name>
        <type>dwelling</type>

        <activity>sleep</activity>
        <activity>eat</activity>
        <activity>watch TV</activity>

    </place>

    <place>...</place>

    <place>...</place>

</places>

How cool would it be to have a JSON object out of this which would represent this exact structure so you'll be able to either:

• Store this object as it is in any CouchDB-like database
• Read it from your $_POST[] server side and retrive a correctly nested array you can then semantically manipulate
• Use some server-side script to convert it into a well-formed XML file (even if you don't know its exact structure a-priori)
• Just somehow use it as it is in any Node.js-like server script

OK, so now we need to think how a form can represent an XML file.

Of course the <form> tag is the root, but then we have that <place> element which is a container and not a data element itself, so we cannot use an input tag for it.

Here's where the <fieldset> tag comes in handy! We'll use <fieldset> tags to represent all container elements in our form/XML representation and so getting to a result like this:

<form name="places">

    <fieldset name="place">

        <input type="text" name="name"/>
        <select name="type">
            <option value="dwelling">Dwelling</option>
            <option value="restoration">Restoration</option>
            <option value="sport">Sport</option>
            <option value="administrative">Administrative</option>
        </select>

        <input type="text" name="activity"/>
        <input type="text" name="activity"/>
        <input type="text" name="activity"/>

    </fieldset>

</form>

As you can see in this form, we're breaking the rule of unique names, but this is OK because they'll be converted into an array of element thus they'll be referenced only by their index inside the array.

At this point you can see how there's no name="array[]" like name inside the form and everything is pretty, simple and semantic.

Now we want this form to be converted into a JSON object which will look like this:

{'places':{

    'place':[

        {

            'name': 'Home',
            'type': 'dwelling',

            'activity':[

                 'sleep',
                 'eat',
                 'watch TV'

            ]

        },

        {...},

        {...}

    ]

}}

To do this I have developed this jQuery plugin here which someone helped optimizing in this Code Review thread and looks like this:

$.fn.toJSO = function () {
    var obj = {},
        $kids = $(this).children('[name]');
    if (!$kids.length) {
        return $(this).val();
    }
    $kids.each(function () {
        var $el = $(this),
            name = $el.attr('name');
        if ($el.siblings("[name=" + name + "]").length) {
            if (!/radio|checkbox/i.test($el.attr('type')) || $el.prop('checked')) {
                obj[name] = obj[name] || [];
                obj[name].push($el.toJSO());
            }
        } else {
            obj[name] = $el.toJSO();
        }
    });
    return obj;
};

I also made this one blog post to explain this more.

This converts everything in a form to JSON (even radio and check boxes) and all you'll have left to do is call

$.post('script.php',('form').toJSO(), ...);

I know there's plenty of ways to convert forms into JSON objects and sure .serialize() and .serializeArray() work great in most cases and are mostly intended to be used, but I think this whole idea of writing a form as an XML structure with meaningful names and converting it into a well-formed JSON object is worth the try, also the fact you can add same-name input tags without worrying is very useful if you need to retrive dynamically generated forms data.

I hope this helps someone!

This is an improvement for Tobias Cohen's function, which works well with multidimensional arrays:

http://jsfiddle.net/BNnwF/2/

However, this is not a jQuery plugin, but it will only take a few seconds to make it into one if you wish to use it that way: simply replace the function declaration wrapper:

function serializeFormObject(form)
{
    ...
}

with:

$.fn.serializeFormObject = function()
{
    var form = this;
    ...
};

I guess it is similar to macek's solution in that it does the same thing, but i think this is a bit cleaner and simpler. I also included macek's test case inputs into the fiddle and added some additional ones. So far this works well for me.

function serializeFormObject(form)
{
    function trim(str)
    {
        return str.replace(/^\s+|\s+$/g,"");
    }

    var o = {};
    var a = $(form).serializeArray();
    $.each(a, function() {
        var nameParts = this.name.split('[');
        if (nameParts.length == 1) {
            // New value is not an array - so we simply add the new
            // value to the result object
            if (o[this.name] !== undefined) {
                if (!o[this.name].push) {
                    o[this.name] = [o[this.name]];
                }
                o[this.name].push(this.value || '');
            } else {
                o[this.name] = this.value || '';
            }
        }
        else {
            // New value is an array - we need to merge it into the
            // existing result object
            $.each(nameParts, function (index) {
                nameParts[index] = this.replace(/\]$/, '');
            });

            // This $.each merges the new value in, part by part
            var arrItem = this;
            var temp = o;
            $.each(nameParts, function (index) {
                var next;
                var nextNamePart;
                if (index >= nameParts.length - 1)
                    next = arrItem.value || '';
                else {
                    nextNamePart = nameParts[index + 1];
                    if (trim(this) != '' && temp[this] !== undefined)
                        next = temp[this];
                    else {
                        if (trim(nextNamePart) == '')
                            next = [];
                        else
                            next = {};
                    }
                }

                if (trim(this) == '') {
                    temp.push(next);
                } else
                    temp[this] = next;

                temp = next;
            });
        }
    });
    return o;
}

Tobias's solution above is the correct one, however, as commenter @macek pointed out, it does not handle inputs of type foo[bar] and split them into sub-objects.

This is a PHP-only feature, but I still find it very useful to be able to generate the same structure in JavaScript.

I simply modified Tobias's code above, so all credit goes to him. This can probably be made cleaner, but I just whipped it up in five minutes and thought it might be useful.

It does not handle multidimensional arrays or numerically indexed arrays at this time. That is, it will only work with names foo[bar] and not foo[].

jQuery.fn.serializeObjectPHP = function()
{
    var o = {};
    var re = /^(.+)\[(.*)\]$/;
    var a = this.serializeArray();
    var n;
    jQuery.each(a, function() {
        var name = this.name;
        if ((n = re.exec(this.name)) && n[2]) {
            if (o[n[1]] === undefined) {
                o[n[1]] = {};
                o[n[1]][n[2]] = this.value || '';
            } else if (o[n[1]][n[2]] === undefined) {
                o[n[1]][n[2]] = this.value || '';
            } else {
                if(!o[n[1]][n[2]].push) {
                    o[n[1]][n[2]] = [ o[n[1]][n[2]] ];
                }
                o[n[1]][n[2]].push(this.value || '');
            }
        } else {
            if (n && !n[2]) {
                name = n[1];
            }
            if (o[name] !== undefined) {
                if (!o[name].push) {
                    o[name] = [o[name]];
                }
                o[name].push(this.value || '');
            } else {
                o[name] = this.value || '';
            }
        }
    });
    return o;
};

I found a problem with the selected solution.

When using forms that have array based names the jQuery serializeArray() function actually dies.

I have a PHP framework that uses array-based field names to allow for the same form to be put onto the same page multiple times in multiple views. This can be handy to put both add, edit and delete on the same page without conflicting form models.

Since I wanted to seralize the forms without having to take this absolute base functionality out I decided to write my own seralizeArray():

        var $vals = {};

        $("#video_edit_form input").each(function(i){
            var name = $(this).attr("name").replace(/editSingleForm\[/i, '');

            name = name.replace(/\]/i, '');

            switch($(this).attr("type")){
                case "text":
                    $vals[name] = $(this).val();
                    break;
                case "checkbox":
                    if($(this).attr("checked")){
                        $vals[name] = $(this).val();
                    }
                    break;
                case "radio":
                    if($(this).attr("checked")){
                        $vals[name] = $(this).val();
                    }
                    break;
                default:
                    break;
            }
        });

Please note: This also works outside of form submit() so if an error occurs in the rest of your code the form won't submit if you place on a link button saying "save changes".

Also note that this function should never be used to validate the form only to gather the data to send to the server-side for validation. Using such weak and mass-assigned code WILL cause XSS, etc.

If you are trying to convert all form fields to JSON in order to submit this form through Ajax here is a jQuery form plugin that does that.

I had to shameless self-promote my form library.

transForm.js

It does things like: serialize, deserialize, clear & submit forms.

The reason why I made this is form2js/js2form is not maintained and is not as flexible & fast as I would like. We use it in production because this is form2js/js2form compatible.

Convert forms to JSON LIKE A BOSS

UPDATE: The following code is now deprecated. You can find the current version on GitHub.

The following code can take work with all sorts of input names; and handle them just as you'd expect.

For example:

<!-- all of these will work! -->
<input name="honey[badger]" value="a">
<input name="wombat[]" value="b">
<input name="hello[panda][]" value="c">
<input name="animals[0][name]" value="d">
<input name="animals[0][breed]" value="e">
<input name="crazy[1][][wonky]" value="f">
<input name="dream[as][vividly][as][you][can]" value="g">

// output
{
  "honey":{
    "badger":"a"
  },
  "wombat":["b"],
  "hello":{
    "panda":["c"]
  },
  "animals":[
    {
      "name":"d",
      "breed":"e"
    }
  ],
  "crazy":[
    null,
    [
      {"wonky":"f"}
    ]
  ],
  "dream":{
    "as":{
      "vividly":{
        "as":{
          "you":{
            "can":"g"
          }
        }
      }
    }
  }
}

Usage

$('#my-form').serializeObject();

The Sorcery (JavaScript)

(function($){
    $.fn.serializeObject = function(){

        var self = this,
            json = {},
            push_counters = {},
            patterns = {
                "validate": /^[a-zA-Z][a-zA-Z0-9_]*(?:\[(?:\d*|[a-zA-Z0-9_]+)\])*$/,
                "key":      /[a-zA-Z0-9_]+|(?=\[\])/g,
                "push":     /^$/,
                "fixed":    /^\d+$/,
                "named":    /^[a-zA-Z0-9_]+$/
            };


        this.build = function(base, key, value){
            base[key] = value;
            return base;
        };

        this.push_counter = function(key){
            if(push_counters[key] === undefined){
                push_counters[key] = 0;
            }
            return push_counters[key]++;
        };

        $.each($(this).serializeArray(), function(){

            // skip invalid keys
            if(!patterns.validate.test(this.name)){
                return;
            }

            var k,
                keys = this.name.match(patterns.key),
                merge = this.value,
                reverse_key = this.name;

            while((k = keys.pop()) !== undefined){

                // adjust reverse_key
                reverse_key = reverse_key.replace(new RegExp("\\[" + k + "\\]$"), '');

                // push
                if(k.match(patterns.push)){
                    merge = self.build([], self.push_counter(reverse_key), merge);
                }

                // fixed
                else if(k.match(patterns.fixed)){
                    merge = self.build([], k, merge);
                }

                // named
                else if(k.match(patterns.named)){
                    merge = self.build({}, k, merge);
                }
            }

            json = $.extend(true, json, merge);
        });

        return json;
    };
})(jQuery);

Use $('#formName').serializeObject()

For a quick, modern solution, use the JSONify jQuery plugin. The example below is taken verbatim from the GitHub README. All credit to Kushal Pandya, author of the plugin.

Given:

<form id="myform">
    <label>Name:</label>
    <input type="text" name="name"/>
    <label>Email</label>
    <input type="text" name="email"/>
    <label>Password</label>
    <input type="password" name="password"/>
</form>

Running:

$('#myform').jsonify();

Produces:

{"name":"Joe User","email":"[email protected]","password":"mypass"}

If you want to do a jQuery POST with this JSON object:

$('#mybutton').click(function() {
    $.post('/api/user', JSON.stringify($('#myform').jsonify()));
}

What's wrong with:

var data = {};
$(".form-selector").serializeArray().map(function(x){data[x.name] = x.value;}); 

This solution is better. Some of the more popular options on here don't correct handle checkboxes when the checkbox is not checked.

       getData: function(element){
      //@todo may need additional logic for radio buttons
      var select = $(element).find('select');
      var input = $(element).find('input');
      var inputs = $.merge(select,input);
      var data = {};
      //console.log(input,'input');
      $.each(inputs,function(){
        if($(this).attr('type') != undefined){
          switch($(this).attr('type')){
            case 'checkbox':
              data[$(this).attr('name')] = ( ($(this).attr('checked') == 'checked') ? $(this).val():0 );
              break;
            default:
              data[$(this).attr('name')] = $(this).val();
              break;
          }
        }
        else{
          data[$(this).attr('name')] = $(this).val();
        }
      })
      return data;
   }