Serializing to JSON in jQuery [duplicate]

Answer 1

The best way is to include the polyfill for JSON object.

But if you insist create a method for serializing an object to JSON notation (valid values for JSON) inside the jQuery namespace, you can do something like this:

Implementation

// This is a reference to JSON.stringify and provides a polyfill for old browsers.
// stringify serializes an object, array or primitive value and return it as JSON.
jQuery.stringify = (function ($) {
  var _PRIMITIVE, _OPEN, _CLOSE;
  if (window.JSON && typeof JSON.stringify === "function")
    return JSON.stringify;

  _PRIMITIVE = /string|number|boolean|null/;

  _OPEN = {
    object: "{",
    array: "["
  };

  _CLOSE = {
    object: "}",
    array: "]"
  };

  //actions to execute in each iteration
  function action(key, value) {
    var type = $.type(value),
      prop = "";

    //key is not an array index
    if (typeof key !== "number") {
      prop = '"' + key + '":';
    }
    if (type === "string") {
      prop += '"' + value + '"';
    } else if (_PRIMITIVE.test(type)) {
      prop += value;
    } else if (type === "array" || type === "object") {
      prop += toJson(value, type);
    } else return;
    this.push(prop);
  }

  //iterates over an object or array
  function each(obj, callback, thisArg) {
    for (var key in obj) {
      if (obj instanceof Array) key = +key;
      callback.call(thisArg, key, obj[key]);
    }
  }

  //generates the json
  function toJson(obj, type) {
    var items = [];
    each(obj, action, items);
    return _OPEN[type] + items.join(",") + _CLOSE[type];
  }

  //exported function that generates the json
  return function stringify(obj) {
    if (!arguments.length) return "";
    var type = $.type(obj);
    if (_PRIMITIVE.test(type))
      return (obj === null ? type : obj.toString());
    //obj is array or object
    return toJson(obj, type);
  }
}(jQuery));

Usage

var myObject = {
    "0": null,
    "total-items": 10,
    "undefined-prop": void(0),
    sorted: true,
    images: ["bg-menu.png", "bg-body.jpg", [1, 2]],
    position: { //nested object literal
        "x": 40,
        "y": 300,
        offset: [{ top: 23 }]
    },
    onChange: function() { return !0 },
    pattern: /^bg-.+\.(?:png|jpe?g)$/i
};

var json = jQuery.stringify(myObject);
console.log(json);