JS: Property Descriptor

What is Property Descriptor

Property Descriptor is the syntax for specifying Property Attributes . It has the form:

{ value: value, writable: boolean, enumerable: boolean, configurable: boolean }

Property Descriptor for Getter Property

{ get: function, enumerable: boolean, configurable: boolean }

• JS: Getter / Setter Property

Property Descriptor for Setter Property

{ set: function, enumerable: boolean, configurable: boolean }

Get Property Descriptor

Property Descriptor is used by several JavaScript functions to create or set properties together with attributes.

• JS: Reflect.getOwnPropertyDescriptor
• JS: Object.getOwnPropertyDescriptors

Set Property Descriptor

• JS: Object.create
• JS: Reflect.defineProperty
• JS: Object.defineProperties

Default Values of Property Descriptor

value

undefined

configurable

false

enumerable

false

writable

false

set

undefined

get

undefined

// check default values of property attributes

const jj = Object.create(Object.prototype, { "p": { value: 1 } });
const xdesc = Reflect.getOwnPropertyDescriptor(jj, "p");

console.assert(xdesc.value === 1);
console.assert(xdesc.writable === false);
console.assert(xdesc.enumerable === false);
console.assert(xdesc.configurable === false);