# Function: updateJson

▸ **updateJson**\<`T`, `U`\>(`tree`, `path`, `updater`, `options?`): `void`

Updates a JSON value to the file system tree

#### Type parameters

| Name | Type                     |
| :--- | :----------------------- |
| `T`  | extends `object` = `any` |
| `U`  | extends `object` = `T`   |

#### Parameters

| Name       | Type                                                                                                                                  | Description                                                                                          |
| :--------- | :------------------------------------------------------------------------------------------------------------------------------------ | :--------------------------------------------------------------------------------------------------- |
| `tree`     | [`Tree`](../../devkit/documents/Tree)                                                                                                 | File system tree                                                                                     |
| `path`     | `string`                                                                                                                              | Path of JSON file in the Tree                                                                        |
| `updater`  | (`value`: `T`) => `U`                                                                                                                 | Function that maps the current value of a JSON document to a new value to be written to the document |
| `options?` | [`JsonParseOptions`](../../devkit/documents/JsonParseOptions) & [`JsonSerializeOptions`](../../devkit/documents/JsonSerializeOptions) | Optional JSON Parse and Serialize Options                                                            |

#### Returns

`void`