Object.getPrototypeOf

Object.getPrototypeOf() 方法返回指定对象的原型 ( 即, 内部[[Prototype]]属性）。

语法

Object.getPrototypeOf(obj)

参数

obj要设置其原型的对象。

返回值

给定对象的原型。如果没有继承的属性，null则返回。

Examples

var proto = {};
var obj = Object.create(proto
Object.getPrototypeOf(obj) === proto; // true

注意事项

在ES5中，TypeError如果obj参数不是一个对象，它将会抛出一个异常。在ES2015中，参数将被强制为一个Object。

Object.getPrototypeOf('foo'
// TypeError: "foo" is not an object (ES5 code)
Object.getPrototypeOf('foo'
// String.prototype                  (ES2015 code)

规范

Specification	Status	Comment
ECMAScript 5.1 (ECMA-262)The definition of 'Object.getPrototypeOf' in that specification.	Standard	Initial definition.
ECMAScript 2015 (6th Edition, ECMA-262)The definition of 'Object.getPrototypeOf' in that specification.	Standard
ECMAScript Latest Draft (ECMA-262)The definition of 'Object.getPrototypeOf' in that specification.	Living Standard

浏览器兼容性

Feature	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari
Basic Support	5	(Yes)	3.5	9	12.10	5

Feature	Android	Chrome for Android	Edge mobile	Firefox for Android	IE mobile	Opera Android	iOS Safari
Basic Support	(Yes)	(Yes)	(Yes)	1	No	(Yes)	(Yes)