---
title: "fold"
description: "fold"
language: "en"
canonical: "https://g2.antv.antgroup.com/en/manual/core/data/fold/"
version: "5.4.8"
---

[Resource index](/llms.txt)

Unfold multiple fields into a specified key-value organization format.

## Getting Started

```ts
const data = [
  { a: 1, b: 2, c: 3 },
  { a: 4, b: 5, c: 6 },
];

chart.options({
  type: 'view',
  data: {
    type: 'inline',
    value: data,
    transform: [
      {
        type: 'fold',
        fields: ['a', 'b'],
        key: 'key',
        value: 'value',
      },
    ],
  },
});
```

After the above example is processed, the data becomes:

```js
[
  { a: 1, b: 2, c: 3, key: 'a', value: 1 },
  { a: 1, b: 2, c: 3, key: 'b', value: 2 },
  { a: 4, b: 5, c: 6, key: 'a', value: 4 },
  { a: 4, b: 5, c: 6, key: 'b', value: 5 },
];
```

## Options

| Property | Description                                           | Type       | Default |
| -------- | ----------------------------------------------------- | ---------- | ------- |
| fields   | List of fields to be unfolded                         | `string[]` |         |
| key      | Field name for the enumeration values after unfolding | `string`   | `key`   |
| value    | Field name for the data values after unfolding        | `string`   | `value` |