Reflect.getOwnPropertyDescriptor

The static Reflect.getOwnPropertyDescriptor() method is similar to Object.getOwnPropertyDescriptor(). It returns a property descriptor of the given property if it exists on the object, undefined otherwise.

Syntax

Reflect.getOwnPropertyDescriptor(target, propertyKey)

Parameters

target

The target object in which to look for the property.

propertyKey

The name of the property to get an own property descriptor for.

Return value

A property descriptor object if the property exists in the given target object; otherwise, undefined.

Exceptions

A TypeError, if target is not an Object.

Description

The Reflect.getOwnPropertyDescriptor method returns a property descriptor of the given property if it exists on the object, undefined otherwise. The only difference to Object.getOwnPropertyDescriptor() is how non-object targets are handled.

Examples

Using Reflect.getOwnPropertyDescriptor()

Reflect.getOwnPropertyDescriptor({x: 'hello'}, 'x');
// {value: "hello", writable: true, enumerable: true, configurable: true}

Reflect.getOwnPropertyDescriptor({x: 'hello'}, 'y');
// undefined

Reflect.getOwnPropertyDescriptor([], 'length');
// {value: 0, writable: true, enumerable: false, configurable: false}

Difference to Object.getOwnPropertyDescriptor()

If the first argument to this method is not an object (a primitive), then it will cause a TypeError. With Object.getOwnPropertyDescriptor, a non-object first argument will be coerced to an object at first.

Reflect.getOwnPropertyDescriptor('foo', 0);
// TypeError: "foo" is not non-null object

Object.getOwnPropertyDescriptor('foo', 0);
// { value: "f", writable: false, enumerable: true, configurable: false }

Specifications

Specification	Status	Comment
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Reflect.getOwnPropertyDescriptor' in that specification.	Standard	Initial definition.
ECMAScript 2017 Draft (ECMA-262) The definition of 'Reflect.getOwnPropertyDescriptor' in that specification.	Draft

Browser compatibility

See also

• Reflect
• Object.getOwnPropertyDescriptor()