`[@@toPrimitive]()` 方法可将 Symbol 对象转换为原始值。

## 语法

    Symbol()[Symbol.toPrimitive](hint);

### 返回值

该原始值为指定的 `Symbol` 对象

## 描述

`Symbol` 的 `[@@toPrimitive]() 方法`返回该 Symbol 对象原始值作为 Symbol 数据形式。 `hint` 参数未被使用。

JavaScript 调用 `[@@toPrimitive]()` 方法将一个对象转换为原始值表示。你不需要自己调用 `[@@toPrimitive]()` 方法；当对象需要被转换为原始值时，JavaScript 会自动地调用该方法。

## 规范

Specification | Status | Comment
--- | --- | ---
ECMAScript 2015 (6th Edition, ECMA-262) Symbol.prototype.@@toPrimitive | Standard | Initial definition.
ECMAScript Latest Draft (ECMA-262) Symbol.prototype.@@toPrimitive | Draft |

## 浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

- Desktop
- Mobile

Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari
--- | --- | --- | --- | --- | ---
Basic support | ? | 44.0 (44.0) | ? | ? | ?

Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile
--- | --- | --- | --- | --- | --- | ---
Basic support | ? | ? | 44.0 (44.0) | ? | ? | ?

## 参考资料

- `Symbol.toPrimitive`