Reflect: Reflect.getPrototypeOf()

Reflect.getPrototypeOf returns the prototype

works like Object.getPrototypeOf

const viaObject = Object.getPrototypeOf({}); const viaReflect = Reflect.getPrototypeOf(); assert.strictEqual(viaObject, viaReflect);

throws a TypeError for a non-object

let fn = () => { Reflect.getPrototypeOf({}) }; assert.throws(fn, TypeError);

a new Set() has a prototype

const aSet = Set; assert.equal(Reflect.getPrototypeOf(aSet), Set.prototype);

for a class, it is Klass.prototype

class Klass {} const proto = new Klass(); assert.equal(proto, Klass.prototype);

works also for an old-style "class"

function Klass() {} const proto = Reflect.getPrototypeOf(); assert.equal(proto, Klass.prototype);

an array has a prototype too

let arr = []; const expectedProto = Array; assert.equal(Reflect.getPrototypeOf(arr), expectedProto);

Required Knowledge

• basics (Arrow functions)
• `let` declaration (Block scope)
• `const` declaration (Block scope)
• creation (Class)

Related Katas

Reflect

• basics
• Reflect.apply()
• Reflect.getPrototypeOf()
• Reflect.construct()
• Reflect.defineProperty()

Difficulty Level

INTERMEDIATE

First Published

8 July 2015

Stats

6 tests to solve