Question

The method Object.defineProperty (see here) accepts as third argument a “descriptor”.

What is a descriptor?

Answer 1

A property descriptor can be of two types: data descriptor, or accessor descriptor.

Data descriptor

Mandatory properties:

• value

Optional properties:

• configurable
• enumerable
• writable

Sample:

{
    value: 5,
    writable: true
}

Accessor descriptor

Mandatory properties:

• Either get or set or both

Optional properties:

• configurable
• enumerable

Sample:

{
    get: function () {
        return 5;
    },
    enumerable: true
}