# flatted

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A super light (0.5K) and fast circular JSON parser, directly from the creator of [CircularJSON](https://github.com/WebReflection/circular-json/#circularjson).

Usable via [CDN](https://unpkg.com/flatted) or as regular module.

```js
// ESM
import {parse, stringify} from 'flatted/esm';

// CJS
const {parse, stringify} = require('flatted/cjs');

const a = [{}];
a[0].a = a;
a.push(a);

stringify(a); // [["1","0"],{"a":"0"}]
```

### New in V1: Exact same JSON API

  * Added a [reviver](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse#Syntax) parameter to `.parse(string, reviver)` and revive your own objects.
  * Added a [replacer](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#Syntax) and a `space` parameter to `.stringify(object, replacer, space)` for feature parity with JSON signature.


### Compatibility
All ECMAScript engines compatible with `Map`, `Set`, `Object.keys`, and `Array.prototype.reduce` will work, even if polyfilled.


### How does it work ?
While stringifying, all Objects, including Arrays, and strings, are flattened out and replaced as unique index. `*`

Once parsed, all indexes will be replaced through the flattened collection.

<sup><sub>`*` represented as string to avoid conflicts with numbers</sub></sup>

```js
// logic example
var a = [{one: 1}, {two: '2'}];
a[0].a = a;
// a is the main object, will be at index '0'
// {one: 1} is the second object, index '1'
// {two: '2'} the third, in '2', and it has a string
// which will be found at index '3'

Flatted.stringify(a);
// [["1","2"],{"one":1,"a":"0"},{"two":"3"},"2"]
// a[one,two]    {one: 1, a}    {two: '2'}  '2'
```