CODEWITHSUNDEEP
javascriptjqueryarraysjsonobject
user3285806
user3285806

Reputation: 117

Convert array of javascript objects to JSON

I have a set of data in the format:

[{"title":movietitle1, "id":445, "release":"16JUN1985"}, {"title":movietitle2, "id":487, "release":"12AUG1993"}]

Which I need to convert into JSON formatted as such:

{ "movietitle1":{"id":445,"release":"16JUN1985"}, "movietitle2":{"id":487, "release":"12AUG1993"} }

I don't have any idea of how to make this happen.

Upvotes: 0

Views: 2431

Answers (3)

Sukima
Sukima

Reputation: 10084

Your mixing terms. I'm assuming you're asking about manipulating data with JavaScript objects and not strings with JSON data. (The later can be converted with JSON.parse).

First iterate over the array and assigning to an object. This kind of data manipulation works well using Underscore, check it out.

In vanilla JS lets try something like this:

var newData = {};
data.forEach(function(item) {
  var title = item.title;
  delete item.title;
  newData[title] = item;
});

A little crufty but gets the job done.

Personally I'd use this Underscore version:

var newData = _(data).chain()
  .map(function(item) {
    return [item.title, _(item).omit('title')];
  })
  .object()
  .value();

Upvotes: 0

Ruan Mendes
Ruan Mendes

Reputation: 92334

What you are asking for is to turn an array into a map , keying by a specific property, If you really want JSON, you can just call JSON.stringify on the resulting JS object.

http://jsfiddle.net/FfE8f/1/

/**
 * Given an array and a property name to key by, returns a map that is keyed by each array element's chosen property
 * This method supports nested lists
 * Sample input: list = [{a: 1, b:2}, {a:5, b:7}, [{a:8, b:6}, {a:7, b:7}]]; prop = 'a'
 * Sample output: {'1': {a: 1, b:2}, '5': {a:5, b:7}, '8': {a:8, b:6}, '7':{a:7, b:7}}
 * @param {object[]} list of objects to be transformed into a keyed object
 * @param {string} keyByProp The name of the property to key by
 * @return {object} Map keyed by the given property's values
 */
function mapFromArray (list , keyByProp) {
  var map = {};
  for (var i=0, item; item = list[i]; i++) {
    if (item instanceof Array) {
      // Ext.apply just copies all properties from one object to another,
      // you'll have to use something else. this is only required to support nested arrays.
      Ext.apply(map, mapFromArray(item, keyByProp));
    } else {
      map[item[keyByProp]] = item;
    }
  }
  return map;
};

console.log(mapFromArray([
    {"title": "title 1", "id":445, "release":"16JUN1985"}, 
    {"title":"movietitle2", "id":487, "release":"12AUG1993"}],
    "title"
)));
// outputs
{
    "title 1": {"title":"title 1","id":445,"release":"16JUN1985"},
    "movietitle2": {"title":"movietitle2","id":487,"release":"12AUG1993"}
}

See More efficient way to search an array of javascript objects?

Upvotes: 0

jshanley
jshanley

Reputation: 9138

You can do this with JSON.stringify() and some basic data manipulation.

Store your data in a variable, lets call it input_data.

Loop through your data and use each entry to build up another variable, lets call it output_data.

// create an object to store the newly formatted data
var output_data = {};
// the code in here is run once for each item in input_data
for (var i = 0; i < input_data.length; i++) {
  // get the current item's title
  var title = input_data[i].title;
  // use the title as the key in the output data
  //  and assign the other values to that key
  output_data[title] = {
    id: input_data[i].id,
    release: input_data[i].release
  };
} 

// use JSON.stringify() to make a valid JSON string
var json = JSON.stringify(output_data);

// now use the variable json which contains your JSON string

Upvotes: 3

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